Senin, 31 Januari 2011

How to Diagnose a 2002 Chevrolet Silverado

How to Diagnose a 2002 Chevrolet Silverado

A 2002 Chevrolet Silverado has many diagnostic systems running at the same time, the most commonly accessed of which are the second-generation On-Board Diagnostic system and the antilock braking system (ABS). Accessing both requires the use of a handheld code reader and the Silverado's data link connector (DLC). The Silverado features other diagnostic arrays, such as those for SRS air bags, and while it can also connect through the DLC, handheld equipment is not readily available for the general consumer.

Instructions

    1

    Open the Silverado's driver-side door. Put you key into the vehicle's ignition cylinder, but leave it unturned for the moment. Look into the driver's side leg space. There, beneath the dash and the steering column, you will locate the Silverado's DLC outlet. It's made either of black or gray plastic and features 16-pin receivers. It will not be concealed behind a trim panel, and it will be out in the open for easy access.

    2

    Connect your diagnostic handheld device to the Silverado's DLC. Most types of scanner use a length of diagnostic cable. The end of this cable features a plug with 16 pins. It will fit the DLC without any problem or need to force it into place.

    3

    Switch on your diagnostic handheld. Turn the key in the SIlverado's ignition. This, in turn, will activate the Silverado's electrical system and central computer. Depending on the brand and type of scanner you are using, you may need to crank the Silverado's engine before the device can sync with the central computer.

    4

    Look at your handheld's screen. If the device has not pulled OBD-II or ABS codes, the manufacturer has not preset your device for code auto retrieval. Consult your device's user's manual for instructions on how to enter a scanning command. Both OBD-II and ABS scanners function differently by brand, and operational procedures differ by device.

    5

    Scroll through the codes once you device has retrieved them from their respective diagnostic systems. You can partially decipher OBD-II codes before looking them up. Each alphanumeric code begins with a letter designating the part of the Silverado affected. "P" stands for "power train," "B" stands for "body," "U" stands for "network connection" and "C" stands for "chassis." Some "B" codes will cover brake functionality, but not those covered by the ABS system. ABS codes are only numerical.

    6

    Look up the meaning of each code that appears on your handheld device. Your device's manual may contain a list of coding definitions. For OBD-II scanners, this list entails the generic codes standard to all post-1996 vehicles. General Motors also has a supplemental list (see the link in the Resources section for these codes). Generally, most vehicle owner's manuals do not contain diagnostic coding references.

    7

    Make a list of every problem currently afflicting your Chevrolet Silverado. If you choose not to fix the problems yourself, this list will save you money at the repair shop, as you will have performed the diagnostics for the mechanic; most garages charge diagnostic fees.

Blower Motor Resistor Problems

Blower Motor Resistor Problems

Your vehicle's heating and air-conditioning system is made up of many electrical components. One of those components is known as the blower motor resistor. This component electronically limits the speed of the blower motor, thereby regulating the speed of the air.

Circuitry

    The blower motor resistor has a small circuit board. With time, the circuit board can become brittle -- from heating and cooling -- and break, causing the resistor to send no power to the blower motor. When this has happened, the blower will no longer move air through the vents.

Coils

    The resistor has a number of coils relative to the number of fan speeds your car has. These coils create the resistance needed to control the fan speed. When one of these coils breaks, the fan will not work on that speed.

Resistance

    Electrical resistance can build up in any electrical system. When the resistance in the blower motor resistor becomes too great, the resistor may not work at all, or your car's fan will remain at the same speed, no matter what setting you put it on.

Minggu, 30 Januari 2011

What Are the Causes of My 2004 Mercury Sable Surging?

What Are the Causes of My 2004 Mercury Sable Surging?

Engine surge isn't an uncommon problem in aging, computer-controlled cars, particularly those like the fourth-gen Mercury Sable and Taurus that use several advanced control systems to keep everything running smoothly. When you encounter surging, always bear in mind that it's the result of the engine either not getting something that it should, or getting too much of a good thing.

The Nature of Surge

    While the layman might call cyclic oscillations in engine rpm "surging," mechanics know it by another name: "hunting." Hunting happens when something goes awry in one of the engine's basic operating variables -- fuel supply, air supply, electrical supply -- and the computer starts adjusting fuel injection timing, ignition timing and air supply in order to find a happy medium. The computer will hunt up and down through ignition and fuel curves until it finds some way to balance air/fuel ratio, engine rpm and operating efficiency to keep things running.

Vacuum Leaks

    Vacuum leaks and leaks around the engine's airbox-to-throttle body tube allow unmetered air into the engine, and that confuses the computer. Normally, air would pass through the mass airflow sensor (adjacent to the airbox), through the tube and into the manifold, where the manifold air pressure sensor will double-check the MAF sensor's readings. If unmetered air gets in after the MAF sensor, the MAP sensor will send a signal to the computer indicating a low-air-pressure condition. The computer may interpret this as a high-altitude reading, and will alter fuel injection and ignition timing to compensate. Once the O2 sensors notice the discrepancy in air/fuel ratio, the computer will revert back to its original setting and begin the process all over again.

Low Fuel Pressure

    Low fuel pressure can happen because of a malfunctioning pump, an obstruction in the lines or dirty enough injectors, but will most often come about as a result of clogged in-tank or in-line fuel filters. Low fuel pressure will have the same kind of effect on your computer as unmetered air sneaking past the MAF; in both cases, you'll wind up with a lean (fuel-poor) mixture and a computer that has to hunt through its settings to compensate. The degree and frequency of hunting will vary depending upon the severity, location and reason for the lack of fuel pressure. Frequently, extremely dirty or clogged fuel injector screens will cause periodic misfire in addition to hunting.

Clogged Catalytic Converter

    The average exhaust system experiences no more than about 3 psi of back-pressure under full-throttle conditions. This is something engineers account for when designing the engine and its control systems, but an extremely clogged or damaged converter will increase exhaust back-pressure and keep more exhaust gases inside the cylinder than would normally be present. This exhaust gas takes up space in the cylinders, effectively reducing engine displacement and confusing the computer. This kind of failure will generally trigger a check engine light when the car's second O2 sensor notices that the converter isn't working.

Ignition System Faults

    Almost any kind of fault in your car's ignition system can result in hunting. The reasoning behind this is the same as that behind the fuel and air issues; the computer expects one thing to happen, and when it doesn't, it tries to adjust to fix it. Your ignition system operates at 100 percent at all times -- the computer doesn't hold anything back in terms of spark energy, so if energy drops then the only thing it can do is adjust fuel injection and ignition timing to compensate. If the computer detects a misfire, it'll play with the ignition advance (moving it forward and back) and the air/fuel ratio (moving it up and down) until the misfire stops or it reaches its safe limits for adjustment. Once the cylinder starts working again, the situation has been resolved and the computer will attempt to return to its original settings.

How to Troubleshoot a Ford EEC-IV

How to Troubleshoot a Ford EEC-IV

Before 1996, each manufacturer had a different diagnostic systems. Ford used Electronic Engine Control, and the fourth version (EEC-IV) came into use with the 1984 vehicles. Troubleshooting engine problems and EEC-IV fault codes involved a process more primitive than today's handheld scanners. Still, initiating an older Ford's self-test is still a relatively easy task. There are two processes for checking EEC trouble codes. One involves counting how many times the check engine light flashes, and the other is necessary for older Fords that do not feature a check engine light.

Instructions

Fords With a Check Engine Light

    1

    Put your key into the ignition and start the car. Let the vehicle idle until the engine is fully warmed. Wait 5 to 10 minutes, or rev the engine at 2000 rpm for two minutes.

    2

    Turn the engine off and engage the parking brake. Make sure the air conditioning is switched off completely.

    3

    Open the hood of the car and locate the Self Test Outlet. The location will differ by model of Ford. The STO is trapezoidal in shape and features six ports. Nearby will be the Self Test Input. It will feature only one port.

    4

    Place a jumper wire into the self test outlet's grounding port. This will either be the right slot on the top row, or the left-most slot on the bottom row. Consult the owner's manual to be certain you are using the right slot.

    5

    Turn the ignition key to "On." The codes will be relayed by the check engine light flashing. Count these flashes. The trouble codes themselves are either two or three digit numbers. There will be a short pause between numbers. For example, code 14 will have the check engine light flash once; then there will be a small pause, and next the light will flash four more times. Longer pauses between lights indicate the end of one trouble code, and the beginning of another. Write down all the codes.

    6

    Turn the Ford off. For EEC code definitions, consult one of the many OBD-I websites available.

Fords Without a Check Engine Light

    7

    Start the vehicle and let the engine warm. Then, turn the engine off.

    8

    Set the volt meter to read between 0 and 15 DC volts. Connect your volt meter's positive lead to the postive terminal on the Ford's battery. Then, connect negative lead to the self test outlet's grounding slot.

    9

    Connect the self test outlet's signal return slot to the self test input with a jumper wire.

    10

    Turn the Ford "On," but do not start the engine. Count the times the needle sweeps. There will be a small pause between numbers within the code. Code 14, for example, will have one needle sweep, followed by a pause and then four more needle sweeps. Long pauses indicate the beginning and end of a new trouble code.

Sabtu, 29 Januari 2011

Problems With Automatic Transmission Linkage

Problems With Automatic Transmission Linkage

The automatic transmission linkage in every automobile has the same function, whether the gears are shifted from the column or on the floor. Problems can occur in the automatic transmission linkage due to normal wear and tear during operation of the automobile. These problems vary, from linkage wear due to use to stretching of the linkage cable.

Broken Linkage

    The automatic transmission linkage will break after it has worn to the point where it cannot change gears. This wear occurs because of internal transmission problems, such as the transmission bands coming loose or the transmission running hot and wearing the internal gears of the automatic transmission. When these internal problems occur, they place more stress on the automatic transmission linkage which slowly wears this mechanical component. The linkage is what turns the gears or shifts them into the desired position, such as park, neutral, drive, first, second, third and overdrive, depending on the model or manufacturer of the vehicle.

Gear Cable

    Every automatic transmission linkage is connected to a gear cable that runs from the gear shift to the linkage. This cable can stretch over normal operation of the automobile. When this cable is stretched, the driver will have difficulty shifting the gears properly. If the cable is stretched too far, then the gear shift will move, but the automobile cannot shift into any gear. The driver will notice that the gear shift does not feel as stiff as it normally does when shifting gears or the gear shift does not align properly with the desired gear. The cable needs to be replaced when these symptoms occur.

Linkage Alignment

    The automatic transmission linkage needs to be aligned properly with the transmission in order for the gear shift to properly change gears. When the gear shift cannot shift the gears into the correct position, the automatic transmission linkage must be adjusted in order to align properly to the corresponding gear. The linkage can become loose under normal operating conditions because of automobile vibration and gear shifting. The linkage needs to be re-adjusted when the gears become hard to shift. The automobile's owner must take the vehicle into a qualified transmission specialist to ensure the linkage is properly aligned.

Jumat, 28 Januari 2011

How to Troubleshoot a Lincoln Town Car

The Lincoln Town Car is a luxury sedan that features a V-8 engine and automatic transmission. Newer models of the car are equipped with satellite navigation, a digital speedometer and parking sensors. As a Town Car owner, you may experience problems with the vehicle from time to time. Basic troubleshooting of some common problems may help you avoid a visit to the mechanic, and also may help you save money in the long run.

Instructions

    1

    Check the fuses if electrical components such as the power seats, horn or power windows do not work. Remove the fuse box cover located on the dashboard and review the diagram on the inside of the cover. Locate the position of the fuse for the component on the diagram. Remove the fuse and inspect it. If the metal link inside it is separated, the fuse is blown. Replace it with a fuse having the same amperage rating. Replace the cover and test the component.

    2

    Check the battery if the engine does not start. Turn on the headlights. If they do not turn on or if they are dim, charge the battery using jumper cables. Connect the positive clamps of the jumper cables to the positive posts on the Town Car battery and the battery of the car providing the boost. Likewise, connect the negative clamps to the negative posts. When the Town Car starts, remove the jumper cables and allow the engine to run for at least 20 minutes to allow the battery to charge.

    3

    Check the position of the shifter if the car does not start when the key is turned in the ignition switch. Make sure the shifter is either in the "Park" or "Neutral" position and you are depressing the brake pedal when you start the engine.

    4

    Contact your mechanic if your car does not start within a few days of being in the repair shop. The mechanic may have forgotten to connect something. Ask the mechanic to recheck the car.

How to Check the Alternator on a 1992 Honda Accord

The alternator in your 1992 Honda Accord is powerful enough to supply all of the electrical requirements for the systems in the car. Symptoms like flickering headlights, a discharged battery, failure to start and others can be caused by a faulty alternator. The average home mechanic can test the alternator and the systems related to it in just a few minutes to pinpoint the cause of a charging system problem. Regular maintenance of the battery and drive belts will help prevent premature alternator failure.

Instructions

    1

    Visually inspect the alternator drive belt for looseness or damage. A damaged, loose or missing drive belt will cause alternator problems. Replace or tighten the belt as needed prior to testing.

    2

    Turn the ignition key to the "Off" position and turn off all electrical accessories like the A/C blower motor and radio. Set your digital volt/ohm meter to measure DC volts.

    3

    Touch the meter leads to the battery terminals, located on top of the battery. The 1992 Honda Accord's battery is located at the front of the engine compartment on the passenger side of the vehicle. Charge the battery, if the voltage is below 12.5 volts, prior to testing. A weak battery can cause a good alternator to appear faulty during testing.

    4

    Start the engine and allow it to idle. Touch the meter leads to the battery terminals and observe the voltage. At idle speed, the 1992 Honda Accord alternator will charge the battery at about 13.5 volts.

    5

    Check the "Charge" fuse. If the voltage observed with the engine running is the same as the battery voltage, check the "Charge" fuse in the fuse block located on the passenger side strut tower, near the firewall. This fuse is a heavy-duty fuse that has a clear top so it can be visually checked. Replace the fuse if the metal bar inside is burned in two pieces.

    6

    Clip the battery clip on the test light cable to the negative battery terminal and touch the probe end to the charging post on the back of the alternator, located below the power steering pump on the driver's side of the engine. The light should be bright and steady. If the belt, battery, fuse and charging post test good, replace the alternator.

Kamis, 27 Januari 2011

How to Test for an Electrical Draw When the Engine Is Off

How to Test for an Electrical Draw When the Engine Is Off

Derived from the Old English word gremain meaning "to vex or frustrate," the Gremlin was thought by turn-of-the-century aircraft mechanics to be a tiny, mischievous creature that invaded biplane electrical systems and caused them to malfunction in flight. Later developments in aircraft maintenance nearly drove the gremlin into extinction, forcing it to flee from its natural high-altitude habitat and into more land-borne conveyances. While once an endangered species, the gremlin has come to thrive in the horrendously complex tangle of wires that is the modern automobile. Fortunately, the gremlin's only natural predator -- the digital multimeter -- is available at any local hardware and requires little persuasion to assist in the hunt.

Instructions

    1

    Set your digital multimeter to read in volts and test the battery voltage. It needs to read at a full charge or close to it of about 12.2 volts so that the battery doesn't throw off your resistance test. Once you've ascertained the battery charge, disconnect the positive and negative battery cables as well as the thick, red cable going to your starter. Unplug any accessories you have plugged into the car, close all the doors and trunk and pull out the light bulb that illuminates your engine bay.

    2

    Set your multimeter to read resistance in ohms and touch the probes to the positive and negative battery cable clamps to test for a major electrical short in the system. The meter should read at least 100 ohms; if it reads 0 ohms then you have a major short. This test isn't technically necessary to test for current draw, but attempting to read amp draw in a system with a major short will probably destroy your multimeter. If you get some kind of ohm reading, then proceed to the next step.

    3

    Reconnect the negative battery cable and set your positive wire terminal next to the positive battery terminal. Do not allow the two to touch. Plug your multimeter's probe wire into the bigger "unfused" terminal and set the multimeter to read current in the 10-amp range. Double check your wire position and multimeter setting; your multimeter is about to become a load-bearing component of your electrical system, so a mistake here will melt the thing into the next world.

    4

    Touch the black probe to the battery cable clamp and the red probe to the positive battery terminal. With all of the doors closed and the accessories off, you should get a reading in the 20 to 35 milliamp -- 0.020 to 0.035 amps -- range. This is pretty typical for the amount of current coursing through the relays and electrical contacts in the off position. Anything higher than that indicates a power draw somewhere in the system.

What Happens When an Alternator Dies?

What Happens When an Alternator Dies?

Electrical system troubleshooting is one of the most basic forms of automotive diagnosis, and it's simpler than you might think. Electrical systems are primarily a matter of supply and demand; you've either got power and a complete circuit, or you don't. The alternator provides that power and helps to complete the circuit, which makes a failure in this department one that can affect your entire car.

Basic Malfunction

    The alternator is, first and foremost, a generator; the faster it spins, the more power it should produce. How that power manifests is up to the voltage regulator inside your alternator, a device responsible for keeping output at a steady 14 volts regardless of alternator amperage production. When the voltage regulator starts to go or the alternator's output drops too low, system voltage will drop. This voltage drop can affect any number of systems in a number of ways.

Lights Dimming

    Your car's lights are one of its most power-hungry accessories, and they're quite sensitive to changes in voltage. A drop in voltage will essentially reduce the temperature of the filament in your light's bulbs, causing them to dim. Lights that get brighter or dimmer according to engine rpm are a classic sign of an alternator failing to produce sufficient power at low rpm. In cases such as this, you may get an alternator or voltage warning light that comes on at idle, but not under cruise or acceleration.

Accessory Performance

    Other accessories in your car need a consistent voltage supply as well. Power windows, the AC blower fan, fuel pump, cooling fan and anything else that uses an electric motor all require a steady supply of voltage to maintain motor speed. While the former will only result in slow accessory performance, the latter may cause reduced engine performance and possibly overheating at idle. The ignition system may suffer as well, but, in most cases, a loss of fuel pressure will hurt performance more than an underpowered ignition system.

Noise

    Alternators can emit a number of noises or smells when they're on their way out. Screeching and whining are fairly common indicators of failure, but you may hear a banging or rattling if something has gone wrong in the mechanical drive system or bearings. A bad alternator may also emit a slight to pronounced odor of electrical ozone, which you may only be able to detect with the engine and cooling fan off.

Battery Effects

    The battery and alternator are, in a sense, the two biggest parts of the same system. A dying alternator will fail to charge the battery, causing it to run consistently low on voltage. The car may prove difficult to start, or it may not start at all. Alternator wires are very close together and close to the case; when they short, they can complete a circuit from the battery to the frame and constantly suck power from it. If you suspect an internal short, then turn the engine off and hold a hacksaw blade to the alternator. If it sticks, then your alternator is drawing power to energize the field coil magnets inside.

Rabu, 26 Januari 2011

How to Test a 1995 Mazda Miata Mass Air Flow Sensor

The 1995 Mazda Miata mass air flow sensor measures the amount of air flow into the engine. The air passes a thin wire in the sensor, and the temperature of the air changes the voltage going through the wire. The sensor then sends a signal, based on the voltage in the wire, to the computer, so that the computer can determine how much fuel is needed for the appropriate air to fuel mixture. The mass air flow sensor is located in the air intake duct on the Miata.

Instructions

DC Voltage Test

    1

    Look at the five wires going into the connector. The wire on the left is the electronic control module, or ECM, ground wire. The second wire is the ground wire. The third wire is the intake air temperature wire. The fourth wire is the mass air flow signal wire, and the fifth wire is the ignition wire.

    2

    Stick the needle into the fourth wire -- the mass air flow signal wire. Attach the voltmeter's red lead to the MAF signal wire and the black lead to a good ground. Turn the key on, but leave the engine off. The voltage should be 0.6 volts. '

    3

    Start the vehicle and allow it to warm up. The voltage should be about 1.3 volts. Slowing bring the rpm up to 2,500 while watching the voltmeter. The voltage should go up to about 1.6 volts. While the voltage is rising it should rise smoothly with no drop outs -- it should never go up then go down as long as the increase in rpm is smooth. Turn the vehicle off.

Out of Range or No Signal Test

    4

    Stick the needle in the ECM ground wire, if the voltage in the previous section was out of range, or if you got no signal when testing. Attach the red lead on the voltmeter to the needle and the black lead to a good ground.

    5

    Turn the key on. The voltage should read below 100mV. If not, replace the MAF sensor. If the voltage is below 100mV, stick the needle into the ignition wire. Attach the red voltmeter lead to the needle. Leave the black lead on a good ground.

    6

    Turn the key on, but leave the engine off. If the voltage is not about 12 volts, replace the MAF sensor.

How to Troubleshoot a 2002 Chevy Malibu

How to Troubleshoot a 2002 Chevy Malibu

The Chevy Malibu is a midsize sedan manufactured by General Motors. It has had two production runs, the most recent beginning in the 1997 model year and continuing to the present day. Common problems with the 2002 Malibu center around the fuel tank, intake manifold gasket and the air conditioning system. Check these areas first when troubleshooting the vehicle.

Instructions

    1

    Check the gas cap to ensure it is tightly sealed. If the cap is loose or has worn threading, it may cause the "check engine" light to come on.

    2

    Check the intake manifold gasket to ensure it is not leaking engine oil or coolant. If a leak is found, the entire gasket must be replaced. Consult your vehicle's repair guide for specific instructions on how to replace the gasket. Consult a qualified mechanic if you feel that replacing this part exceeds your comfort or mechanical skill level.

    3

    Check your vents to determine whether or not air is blowing when you turn on the heat or air conditioning. If no air is flowing, the blower motor may have failed because of a bad resistor assembly. If this is the case, the blower motor will need to be replaced.

Selasa, 25 Januari 2011

How to Check A/C Refrigerant

Checking your A/C refrigerant may prevent costly repairs according to Car Care's website. Your car's A/C, or air conditioner, cools with the help of a refrigerant. Cars manufactured after 1994 use R-13a instead of the R-12 freon used in previous models. R-13a is more environmentally friendly than the R-12 freon. However, the two do not mix, so make sure you know what type your car's A/C uses.

Instructions

    1

    Read your automobile owner's manual. Review the diagram showing your HVAC system. Also, locate the information in the manual providing the type of refrigerant your system uses. If it is not in the manual, look for a label under the hood indicating the type of refrigerant.

    2

    Locate the A/C, or HVAC, unit under your car's hood. Find the low-pressure line on the HVAC system. It is a large line that is steel and looks different from the other hoses and lines under the hood.

    3

    Remove the blue cap on the end of the low-pressure line. Unscrew it using your hand by turning it to the left.

    4

    Connect the A/C pressure gauge to the line. Use the quick-connect snap fitting on the gauge.

    5

    Look at the gauge. The gauge measures pressure in pounds per square inch, or psi. Most gauges have a colored band on the gauge for accuracy. Generally, a reading that falls within the green band indicates your refrigerant level is adequate. However, a reading in the red band indicates low levels.

Leaking Antifreeze After a Changed Water Pump on the 2000 Chevy Blazer

The Blazer debuted in the 1969 model year as a full-sized SUV. In 1983 -- a year after the S-10 debuted -- Chevrolet released a mid-sized SUV: the S-10 Blazer. The Blazer and S-10 Blazer continued side-by-side until the 1995 model year, which was the year that Chevrolet dropped the "S-10" from the mid-sized Blazer and changed the full-sized Blazer's name to the Tahoe. There are five potential causes for a leak after replacing the water pump on the 2000 Blazer's 4.3-liter engine.

Dirty Mating Surfaces

    On important step that some inexperienced do-it-yourself mechanics may overlook is cleaning the mating surface between the engine block and the water pump: Prior to installing the water pump on your 2000 Blazer, you must scrape the water pump mating surface on the engine block with a plastic scraper, then wipe it off with a clean lint-free cloth.

    This eliminates any remnants of the old gasket and any dirt that may be present on the mating surface. If dirt, debris or small pieces of the gasket remain on the mating surface, it will typically result in a leak, as they will break the seal of the water pump gasket.

Incorrect Torque

    The 2000 Blazer's water pump requires you to torque the water pump bolts to 30 foot-pounds. Under-tightening the bolts does not allow the gasket to seal the gap between the water pump and engine block. Over-tightening the water pump bolts may lead to cracks in the gasket, causing the coolant to leak. Over-tightening can also result in the water pump housing to crack, thus creating a leak.

Bolt Seepage

    The water pump bolt threads inside the 2000 Blazer's engine block slowly stretch over time, and may allow the coolant to seep through the gap between the bolt threads and the threads in the engine block. For this reason, Chevrolet recommends applying a coat of RTV silicone to the water pump bolts before tightening them. As the silicone dries, it seals the gaps between the threads.

Hose Connection

    There are three hoses that connect to the 2000 Blazer's water pump. Hose clamps seal the end of each hose to the pump. If you install weak or broken clamps, or do not tighten them properly, coolant can slowly seep from the end of the hoses, resulting in a coolant leak.

Forgotten Gasket

    The 2000 Blazer's water pump requires a total of three gaskets to seal it. There are two gaskets that seal the engine-to-water pump mating surface, and one gasket that seals the water pump's backing plate. If you forget to install one or more of the gaskets, the Blazer will leak coolant quickly.

    On most aftermarket water pumps, the manufacturer installs the backing plate gasket prior to shipping it to vendors. For this reason, you typically do not need to install this gasket.

Water Pump Failure

    The replacement water pump for the 2000 Blazer undergoes a series of tests by quality inspectors to assure it operates correctly. Unfortunately, with any human-controlled process, there is the chance of human error. If an inspector misses an incorrectly cast water pump housing, or other defects, it may fail as soon as you install it and run the engine for the first time. Most new water pumps have a warranty against these types of defects, so you can likely return it to the vendor for a new one.

Nissan Code P0440

Nissan Code P0440

A P0440 error code on your Nissan means there is an evaporative emission control system (EVAP) malfunction. Typically no symptoms of this problem appear, but the error code will cause problems with emissions testing and may indicate dangerous fuel leaks.

Function

    The EVAP system controls the transmission of fuel vapors in order to prevent leaks of flammable gasoline into the air. The Nissan EVAP system consists of a gas cap, the fuel lines, a carbon or charcoal canister, a purge valve and assorted hoses.

Considerations

    The P0440 error could be caused by several issues. The first potential issue to check is that the gas cap is on and tightened properly. Open and replace the gas cap, then reset the error code. Use your vehicle as usual for the next 24 to 48 hours, and see if the error P0440 returns.

Other Causes

    If the error continues to display after you have checked the gas cap, likely there is a leak somewhere in the EVAP system. Inspect all hoses for leaks, or take the Nissan to a local repair shop or dealership to test the system with a smoke machine that will detect leaks. If there are no leaks, then there might be a problem with the purge solenoid on your Nissan, or the carbon canister may have a clog or some other dysfunction.

How to Check a Thermostat in a Car for Problems

How to Check a Thermostat in a Car for Problems

Watching the temperature gauge in your car stay low after a few miles of driving can be worrisome or just plain scary if the gauge is warning you of an overheating engine. A stuck thermostat in the open or closed position is a common problem in an automotive cooling system after miles of service, and a relatively inexpensive repair job. But before you go and buy a new replacement, check the thermostat and make sure you need to install a new unit.

Instructions

    1

    Open the hood of your car and locate the thermostat housing. Depending on your particular vehicle year and model, the upper or lower radiator hose connects to the housing, which mounts on the engine with two or three bolts.

    2

    Remove the radiator cap, if one is provided. Or make a note of the coolant level on the coolant reservoir. This is the plastic bottle on the passenger's side of the engine compartment and connected to the radiator through a rubber hose.

    3

    Set your transmission to Neutral, apply the parking brakes and start the engine. Let the engine idle and walk around the front of the car.

    4

    Watch the coolant. If you see the coolant flowing through the radiator neck, or the level drops on the reservoir, the thermostat is probably stuck open. Wait for 10 minutes, then momentarily touch the engine block next to the thermostat housing and the radiator hose connected to it with the tip of your fingers. Both surfaces should have about the same temperature, if the thermostat is stuck open. Turn off the engine and replace the thermostat.

    5

    Wait for a few minutes to allow the engine temperature to go up, if the coolant is not flowing as you watch through the radiator neck or the level remains the same in the reservoir. Before the temperature gauge reaches the red line, you should see the coolant beginning to flow through the radiator neck or the level drop in the reservoir. If not, momentarily touch the engine block next to the thermostat housing and the radiator hose connected to it with the tip of your fingers. If the engine surface feels hotter than the hose surface, the thermostat is stuck closed. Turn off the engine and replace the thermostat.

Overheating Due to Overfill of Coolant

Overheating Due to Overfill of Coolant

Coolant, also known as antifreeze, is an essential part of maintaining optimal car function. The main ingredient in antifreeze is glycol, with most modern car engines using a mixture of glycol and water. Filling and maintaining your coolant is a relatively simple procedure. However, if it is not done properly, you can cause serious damage to the engine of your car. If you are unsure about to correctly measure the coolant for your car, have it done by a professional auto repair person, who also can show you how to refill the coolant yourself.

What is Antifreeze?

    The main purpose of antifreeze is to lower the freezing point of water during the winter, and raise the boiling point during the summer. For cars, this can be a necessary part of vehicle maintenance if you live in extreme climate conditions. After being placed in the car, the antifreeze circulates through the engine system. The coolant runs through the internal combustion system, preventing the different sections of the vehicles engine from becoming too hot.

Overheating: Too much Coolant

    Using straight antifreeze in your car can be just as, if not more detrimental, than no antifreeze at all. Antifreeze must first be mixed with water to produce the desired effects for your engine. Simply running antifreeze through your system alone can cause extremely high temperatures in your engine, resulting in overheating. If you have mistakenly filled your car with only antifreeze without pre-mixing the substance, loosen the bottom radiator hose and drain about half of the coolant. Add water to make about a 50/50 antifreeze water mixture.

Lack of Coolant

    A refractometer is the best method for measuring how much antifreeze you have in your car. Too much coolant can cause significant problems to your vehicle. Overheating, as previously described, corrosion, water pump failure and increased engine wear. Too much water however, results in a mixture that will not produce the desired effects of using coolant in the first place. In some instances, for example in very moist and hot temperatures, lack of coolant can also cause your engine to overheat. Without enough coolant, there is no substance to absorb and remove the excessive heat in the engine. Unless you are clear on how to properly refill the coolant in your car, it may be worth the expense and trouble of having a professional do it for you.

Coolant Types

    Different types of coolant are available, depending on the climate in which you live and your specific needs. Coolants usually are made of either ethylene glycol or propylene glycol. It is recommended that you do not mix different kinds of coolants, but flush your system before adding a different type. A new type of coolant available is referred to as "long life" coolant. This type of coolant contains organic acid inhibitors and is thought to last longer than other kinds of coolant.

The Cooling System

    The cooling system of an engine is a sealed system. As the pressure in your engine system increases, the temperature will increase. As the water in your engine increases past the boiling point, the water will turn into steam, which is not as effective as liquid at keeping your engine cool. By adding coolant to your engine system, you increase the boiling point of the water, allowing your engine to stay properly cooled. Otherwise, you will experience overheating of the engine.

Senin, 24 Januari 2011

Heater Coil Problems

Heater Coil Problems

An automotive heater coil, more properly referred to as a heater core, is used to provide warm air to heat the passenger cabin of a vehicle as well as to defrost windows. The heater coil looks and works like a small radiator.

Hose Leaks

    A heater coil is served by flexible hoses that allow warm engine coolant to pass through and heat the coil. These hoses can become cracked and leak. Replacement of the hoses is simple, requiring only a replacement hose, hose clamps and a screwdriver.

Clogged Heater Coil

    Heater coils can become clogged with sediment from the engine's coolant. To remove a clog, the heater coil must be back-flushed with water. By removing both of the hoses running to the heater coil, water can be forced into the outlet hose to push clogs back out of the heater coil. Only a minimal amount of pressure should be used to avoid damaging the heater coil.

Coil Leaks

    A heater coil may develop leaks for a number of reasons, with internal corrosion being the most common. Radiator stop-leak additives can be placed in the coolant to address small leaks in the heater coil, but larger leaks will require a physical repair like soldering or replacement. Heater coils are often difficult to access, which will increase labor time and the cost of the repair.

2006 Dodge Stratus Won't Crank

A Dodge Stratus, even one as recent as the 2006 model year, may not be cranking due to either mechanical or electrical issues. It is entirely possible the mechanical parts have suffered wear and tear to the point of breakdown if proper maintenance intervals have not been followed. However, if proper maintenance has been kept up then the problem is most likely a dead battery. This can be rectified with a few steps to either start the car or to determine if the problem is mechanical in nature.

Instructions

    1

    Start the Stratus by turning the key. Listen for chugging to indicate engine turnover. If the engine does not turn over, then look at the dashboard lights for flickering. If the lights do not come on then the battery is dead or dying and needs a jump or replacement.

    2

    Turn the car off and open the hood. Look at the car battery for foam. If there is foam, the battery is leaking acid. A tow truck is needed as a professional mechanic has to deal with the battery, due to possible acid burns. If there is no foam, strike the battery post clamps with a rubber mallet to reconnect the clamps. Try starting the Dodge Stratus; if it does not turn over and start, then the battery must be replaced.

    3

    Park another car hood to hood with the Dodge Stratus. Connect the red jumper cable to the positive terminal on the Stratus and the other end of the red cable to the positive terminal on the other car. Connect one end of the black cable to the negative terminal on the other car and the other end to a bare metal part of the Dodge. Start the good car, and let it idle for five minutes, and start the Stratus. Let the Stratus run for half an hour, to fully recharge the battery, or you can quickly burn out the alternator, which charges a cars battery. If this does not work, your battery needs to be replaced.

    4

    Turn the Stratus off so you can safely remove the battery. Take off the battery post clamps, by unscrewing the O-ring clamps with a flathead screwdriver and remove the retaining clamps with the flathead screwdriver. Pull the battery out by the handle and slide in the new battery. Screw down the retaining claps and electrical clamps, being careful to not over-tighten the screws. The engine will crank now.

How to Tell When a Crank Sensor Goes Bad

Crankshaft and camshaft position sensors are arguably the two most vital sensors on your vehicle's engine. A CPS works something like a super-accurate tachometer: It records the speed at which the engine revolves, but it also determines exactly where the crankshaft is positioned in that rotation. Every single parameter of the engine computer's programming literally revolves around this information, which means that a failing CPS can easily manifest itself as a failure in two or three different systems; therefore, rather than try to diagnose the engine by its symptoms, you'll be far better off testing the sensor output directly.

Instructions

    1

    Take your car to your nearest chain auto-parts store and ask the the mechanics to check the codes, using a scanner. As long as you have an actively-illuminated "Check engine" light, the odds are that the computer codes will reveal the problem.

    2

    Identify the crankshaft position sensor; logically enough, you should find it somewhere near the crankshaft pulley. You may find the sensor mounted onto the timing cover, the engine block or a separate bracket. Identify the wire(s) coming out of the CPS and trace them over the engine. You may want to pull the wires out of the wiring conduit to separate them. Unplug the CPS from the wiring harness.

    3

    Poke the positive (red) needle probe into the plug terminal of the lighter of the two or three wires coming out of the CPS. This wire will typically be white or red. Poke the black needle probe into the terminal corresponding to the darkest wire (usually brown or black, but sometimes green) or touch it to the negative battery terminal, if you have a one-wire CPS.

    4

    Set the digital multi-meter to Ohms of resistance, as indicated by the Greek symbol "." Compare the reading to the CPS resistance specified by your reference manual. If you have excess resistance, then the sensor is bad. If not, plug the harness back in and poke the tips of the needle probes into the wires that correspond to the terminals that you just tested -- the red probe into the red or white wire, and the black probe into the black, brown or black wire.

    5

    Test the sensor output in milliamps while an assistant starts the car. Compare the sensor output to the output described in your vehicle's reference manual. You may need to have your assistant rev up the engine to a certain rpm to test the sensor output at different rpm ranges.

Minggu, 23 Januari 2011

What Is the Purpose of the Oil Pan Gasket?

Just about everything in your car that processes and contains fluid has a gasket to help retain those fluids. The oil pan gasket keeps your car from losing the oil that runs its engine.

Function

    A gasket is a seal fitted between fixed objects that are infrequently taken apart; it is a static seal, meaning it isn't meant to move around. Because you may have to repair/replace your oil pump, removing the oil pan will be required. This means that the oil pan gasket must be properly installed to seal dirt out and keep oil in the pan when reassembling the parts.

Material

    For a proper seal, it is essential that the right gasket material (often made of rubber) is used for the type of metal the oil pan is made of. The material is designed to handle fluctuating temperatures that can cause pressure that otherwise could create oil leakage.

Considerations

    An oil pan gasket, when properly installed, should hold oil in the oil pan unless it has dried and cracked. Inspect where the leak is coming from before having the gasket replaced because it may be caused by a loose oil pan drain plug or oil filter.

Specifications for an HEI Distributor

Specifications for an HEI Distributor

High Energy Ignition distributors were introduced by General Motors in the early 1970s and soon became standard equipment on all models. Solid-state components provided a level of power and reliability far superior to any breaker-point style distributors. Distributor maintenance needs were greatly reduced and usually limited to rotor replacement. The HEI design eliminated the weakest links of presiding ignition systems and are still a potent means of delivering high voltage to the spark plug.

Ignition Coil

    With an ohmmeter set to the lowest scale, place one test lead on either of the coil's primary wires. The reading should be close to 0 ohms, and no more than 3 ohms. Adjust the ohmmeter to the highest scale, and move one test lead to the coil secondary discharge brush in the center of the distributor cap. Repeat this test on the other primary coil wire. The coil is considered defective only if both readings are infinity.

Pickup Coil

    The pickup coil resistance is measured at the ignition module connector, with the connector unplugged. The resistance between the two leads should be in the range of 500 to 1500 ohms. Move the pickup coil leads while monitoring the ohmmeter. No value changes should occur while lightly twisting and pulling on the leads. The resistance between either pickup coil lead and the metal distributor body should be infinite under any circumstance.

Vacuum Advance

    The amount of spark timing advance provided by the vacuum advance varies by year make and model. Normal vacuum advance action can place stress on the pickup coil leads and create a temporary open condition between the pickup coil and ignition module. Sudden stalling occurs when the leads are stretched by the application of vacuum to the advance diaphragm. This condition is most common among Pontiac and Oldsmobile V-8 applications and easily determined by blocking the vacuum signal.

Mechanical Advance

    Ignition timing advance may also be provided by centrifugal weights that react to increases in engine speed. Incomplete movement of the weights can retard the advance curve, or permit advanced timing when there should be none. Sticking weights can frustrate attempts to set the base timing and are repaired by disassembling and cleaning the distributor shaft. Centrifugal weights and their return springs are sometimes modified for custom applications by those with intimate knowledge of the practice.

Ignition Modules

    As with base timing specifications, ignition modules vary by application. Testing the ignition module in the car is difficult and may be inconclusive. Auto parts stores usually provide module bench testing at no charge, but a visual inspection could reveal defects that affect module integrity. Any warp-age or blistering of the module body indicates impending failure. Corrosion on the under side of the module signifies a lack of contact and should be corrected by replacement.

How to Reset the Error Code on the PT Cruiser

How to Reset the Error Code on the PT Cruiser

The "service engine soon" light comes on when the PT Cruiser's computer sends an error code for one of the sensors. The only way to get the error code to remain off is to fix the problem before resetting the code. If the PT Cruiser displays several codes that do not seem to be related, plus erroneous codes, the computer itself is probably bad. The computer cannot diagnose itself, so the only way it can communicate that there is something wrong is by sending incorrect and/or erroneous codes.

Instructions

    1

    Plug the code scanner into the data port, which is located under the driver's side dash, just to the left of the steering column.

    2

    Press the "Read' button. Write down the codes from the scanner's screen. There could be one or more. Translate the code, using the code book that comes with the scanner. Repair the PT Cruiser as needed.

    3

    Plug the code scanner back into the data port after the vehicle is repaired. Press the "Erase" button to erase the codes and reset the computer.

Sabtu, 22 Januari 2011

Troubleshooting a 1996 Integra Power Window Power Lock

Troubleshooting a 1996 Integra Power Window Power Lock

Honda's 1996 Acura Integra was sold with power windows and power door locks. Each door has a switch that controls its window. In addition, the driver's armrest has a master power window control panel that can be used to control all of the windows. Locks are also electrically operated. Power locks include doors and trunk but not the lockable glove compartment. Problems with the power windows and locks can be related to them not working properly, or unexpected operation. These kinds of problems can be corrected by following some troubleshooting.

Instructions

    1

    Press the "Main" switch on the driver's door armrest if the rear windows won't power down. The "Main" switch is forward of the four individual window switches on the armrest. You can keep the switch off when you have children in the car to stop them playing with the windows.

    2

    Press the driver's window switch firmly and release it to automatically send the window all the way down if the window doesn't operate in the "Automatic" mode. The push needs to be firm. Push the switch up momentarily to stop the window from lowering. Note that the other windows don't have an automatic function, so this feature won't work on the other windows.

    3

    Turn the key in the driver's side door and release it if all of the doors unlock and you don't want them to. For security purposes, you may only want the driver's door to unlock. Don't turn the key and hold it, because all of the doors will unlock.

Stewart Warner RPM-Measuring Tools

Maxima Technologies is a company that specializes in electronic equipment, including gauges and fuel sensors, and one of its brands is Stewart Warner, which creates instruments that allow you to monitor and obtain data on different vehicle systems. It also allows you to view information on revolutions per minute on diesel engines. The common name for this type of device is a tachometer.

World Wide

    The World Wide Instruments displays data in both the English and Metric measuring systems, and it features a black dial with white and orange lettering. The meter also features Society of Automotive Engineers (SAE) symbols, and it is made of stainless steel to resist rusting. Other features of this tool include that is has a 12 volt lamp and a white ring lighting, which you can use for electrical gauges. With this tool, you can view information on engine oil pressure, air pressure, fuel level and water temperate. The tool also acts like a voltmeter, which you can use to measure the electrical difference between two opposing points. The World Wide Instrument also acts like a tachometer and ammeter, which you can use to measure how much electrical current is moving through a circuit. As of 2010, this product costs approximately $15.

Deluxe

    The Deluxe is a set of gauges, tachometers and speedometers come. You can get these scales in either the English or Metric measuring system for work on either vehicles or marine systems. With this set, you can get a speedometer for either a vehicle or a boat, a standard tachometer, a diesel tachometer and a gas/ignition tachometer. The tool set comes with a light so you can view the face even at night, and it is made of stainless steel. As of 2010, these gauges cost between $56 and $130, depending on the features that you need.

Standard Line Instruments

    This is a set of gauges. The vehicle gauge is made of stainless steel. It comes with an ammeter and pressure, fuel level gauge, oil pressure and water temperature gauge. The Pro version of this kit comes with an external 12 volt light for night-time use. Each tool has a sealed case to maintain air pressure and to resist corrosion. As of 2010, this product costs between $50 and $100.

Range Rover Valve Block Help

Range Rover Valve Block Help

The high-end Range Rover vehicle uses a different type of car suspension, called Electronic Air Suspension, or EAS. Within this air suspension is a component called the valve block.

Function

    The Range Rover's EAS system automatically adjusts the suspension to the driving conditions and to the vehicle's combined weight with a cargo load. The valve block is made up of a set of valves; these valves control the flow of air from the vehicle's air compressor to the suspension.

Effects

    The valve block is a relatively simple mechanism; however, a problem, such as a leaking valve or cracked block, will affect the performance of a Range Rover. The suspension cannot function without proper air pressure, and a professional must replace a seal for each leaking valve. If the block is cracked or damaged in any way, a professional must replace the entire valve block assembly.

Considerations

    The EAS computer controller software is quite complex, and software issues may contribute to poor air suspension. The Range Rover must be serviced by a factory technician if the software malfunctions.

Jumat, 21 Januari 2011

Chrysler LeBaron Transmission Problems

Introduced in 1931, the Chrysler LeBaron was originally a high-priced luxury car known as the Chrysler Imperial LeBaron. A lower-priced LeBaron was introduced in 1977, two years after the Imperial model was discontinued. Despite its rich history, the LeBaron is not exempt from mechanical problems. In particular, early 1990s LeBaron models suffered from automatic transmission failure.

Failure

    MSN Auto indicates that automatic transmission failure is a common problem with 1991 and 1992 LeBaron models. About Automobile indicates that drivers reported transmission failure while driving at various speeds or while attempting to start the vehicle. One possible reason for transmission failure is a faulty transfer case/snap ring, which is a metal ring in the transmission. If a failing ring is not replaced, it breaks, sending metal fragments throughout the transmission.

Warning Signs

    LeBaron drivers reported several warning signs including difficulty shifting gears due to the damaged snap ring. Additionally, drivers reported that the transmission locked in second gear and/or shifted into reverse without warning.

Solution

    As of 2011, Auto MD estimates that the cost to replace a damaged snap ring is $80 for parts and labor. If the transmission is significantly damaged due to a broken snap ring, MSN Auto estimates that the cost to repair an automatic transmission is $1,599 for parts and labor.

Ford OBD-II Code 320

Ford OBD-II Code 320

Like all cars today, Ford uses on-board diagnostics to help identify faults in car performance. Some of the codes are generic and common to all cars; others are codes specific to Ford's use for its models and engine designs. Fault code P0320 is one of these messages.

Codes

    On-board diagnostics II, also known as OBD-II, is the data language used by car computers to signal when a problem is occurring in the car's performance. The data is pulled from the car by using an OBD-II scanner/reader tool. Repairs are then made, consistent with the code readings.

The P0320 Code

    P0320 is a code signifying an Ignition/Distributor Engine Speed Input circuit fault. This code reflects the data measured tracking the engine ignition timing. If the engine timing is off, the code will be sent by the ignition sensors to the car's computer as a warning. This in turn will trigger the check-engine light and a code specifying repair is needed.

Response

    Mechanics using code P0320 as a signal on a Ford car will look to see that the connection and wiring on the related sensors are working properly. The signal can be sent by loose wires as well as bad ignition. A mechanic will also check the spark plugs and ignition coil for any flaws as well.

Why Electronic Fuel Injectors Can Leak Gas

Why Electronic Fuel Injectors Can Leak Gas

A leaking fuel injector causes a number of problems for an automobile engine. The leaking injector will make the engine less efficient and increase fuel consumption; it may also be a fire hazard. Injector leaks require repair or replacement to restore proper engine function.

Purpose

    Electronic fuel injectors provide gasoline to the combustion chambers of an automobile engine. The amount of gasoline used will vary depending on engine load, making fuel injector operation important to optimal engine performance. Leaking injectors will impact fuel use, engine temperature and emissions.

Causes of Leaks

    The most likely cause of fuel injector leaks is seal or gasket failure. Such failure will create either an intake vacuum leak or an external fuel leak. A fuel injector may leak because contaminants in the injector prevent it from closing. Electrical connectors in the injector may also fail and cause the injector to stay open. Either problem will result in internal engine leaks.

Solutions

    Fixing an external gasket failure requires replacement of the gasket. The seals are typically rubber O-rings that slip off and on the injector. Fuel injector cleaning additives may remove contaminants in the injector and restore proper performance. However, problems with internal seals or electrical connectors will require replacement of the entire injector.

How to Troubleshoot a Chevy Four-Wheel Drive

How to Troubleshoot a Chevy Four-Wheel Drive

Chevy uses an electronic control to transfer the power from two-wheel drive to four-wheel drive. It's no longer necessary to exit the vehicle and manually lock the hubs on the front wheels. This 4x4 system is operated with a transfer case knob on the dash board. Some Chevy systems are two-speed and some single speed. The most elaborate systems have five driving settings. Problem with the system can often be related to knob settings.

Instructions

    1

    Turn the transfer case knob that's to the left of the steering wheel to the two-wheel drive position that's marked with a "2" and up-arrow icon if you experience a vibration in the steering when driving on dry pavement or making tight turns. The laws of physics mean that a tight turn in four-wheel-drive causes forces to work against each other.

    2

    Check the indicator lights in the knob to find out what driving setting you are in if the vehicle exhibits any unusual behavior. The lights will correspond to the "2" and up-arrow position for two-wheel-drive high, "4" and down-arrow for four-wheel drive low, and so on. Wait for flashing lights to stop before shifting the knob.

    3

    Don't shift the knob too frequently if the transfer case enters shift protection mode. Shift protection mode comes into play to stop damage. It will stop the transfer case from shifting for ten seconds at a time. This protection mode can stay in place for up to three minutes.

Kamis, 20 Januari 2011

How to Test a Three-Prong Flasher Relay

How to Test a Three-Prong Flasher Relay

Flasher relays control the operation of turn signals and hazard flashers on many cars and motorcycles. When a flasher relay malfunctions, the turn signals and hazard lights might glow dimly while the flasher itself emits a buzzing sound; not blink at all; pulse without turning completely off; or blink too quickly. If your vehicle is exhibiting any of these symptoms, testing the flasher relay is a good second step in diagnosing the problem (after checking for burnt bulbs) because flashers are prone to fail periodically and depend on a specific load to operate properly.

Instructions

    1

    Identify the terminals. Flasher relays have a power source terminal, sometimes labeled "B" for battery, a load terminal labeled "L" and a panel, or dash-indicator terminal, labeled "P." The circuit diagram is usually printed on the case to facilitate identifying these. If they are not labeled, use an ohm meter to determine which prong is open at rest, i.e., has infinite resistance across to either of the others. This is the "P" terminal. The other two are interchangeable.

    2

    Clip the test light lead between the "P" terminal and the negative terminal of the battery.

    3

    Connect the "B" terminal to the positive terminal of the battery using the test wire with equal-length stripped ends, with one clip on each end.

    4

    Wrap the long-stripped end of the second piece of wire around the base cylinder of the test bulb, securing it with a twist, and connect the short-stripped end to the "L" prong using the third clip.

    5

    Place the center connector of the test bulb on the battery. At this point, the unit should start flashing, causing both the test light and the load bulb to blink. (The action will be twice as fast as usual because the test bulb represents half the normal load on the relay.) If the bulb and the test light blink at regular intervals, the relay is functioning properly. Otherwise, the unit needs replacement.

2003 Chevy Malibu Won't Start

2003 Chevy Malibu Won't Start

The Chevy Malibu is a medium sized car that had two separate production runs, with a 14-year gap in between. Also available in a station wagon model, the sedan version of the Malibu has been used in NASCAR races. If you have a 2003 Malibu that won't start, your car's troubles can probably be isolated in the ignition system, the battery or the fuel delivery system. Following a few simple steps can help you identify the problem with your Malibu.

Instructions

Engine Cranks But Won't Start

    1

    Fill the fuel tank with gasoline. An empty gas tank is a typical culprit in this scenario.

    2

    Ensure that all the spark plugs are solidly connected. If they are, use a spark tester to make sure none of them have gone bad.

    3

    Put the key in the Malibu's ignition and turn the car on. If the fuel pump doesn't make a sound with the key turned on, it is probably malfunctioning and you should consult a mechanic.

    4

    Consult a mechanic to have the timing belt inspected.

Engine Won't Crank

    5

    Move a running vehicle close to the Malibu and hook up jumper cables between the two vehicles' batteries to jump start the Malibu.

    6

    Allow the motor to run for several minutes before removing the cables and turning off the Malibu.

    7

    Try to start the Malibu again. If it doesn't start, the battery needs replacement.

    8

    Consult an automotive technician to test the starter and ignition system if the vehicle will not start with a jump start.

How to Troubleshoot the Transmission in a 1995 Chevy

How to Troubleshoot the Transmission in a 1995 Chevy

The transmission on your 1995 Chevy could eventually start to slip gears. You might think you have to take the car to the transmission shop if this happens to you. Actually, you can do some basic troubleshooting at home. You may be able to avoid a costly trip to the shop. It will take you a couple of hours to troubleshoot your 1995 Chevy's transmission.

Instructions

    1

    Check the spot area where you park your Chevy overnight. If there is a spot of red fluid, then you have a transmission leak. A leak of transmission fluid can lead to a broken transmission.

    2

    Take your Chevy out for a drive to heat up the transmission. Park the vehicle and let it remain running. Pop up the hood and find the transmission dipstick. It will be located on the side of the engine near the rear firewall.

    3

    Pull the dipstick out and clean it off with the old rag. Put the dipstick back in and take it back out right away. Examine the level of the transmission fluid. If the transmission fluid is low then add fluid. Low fluid is a major cause of transmission failure.

    4

    Make sure that the fluid is clean. If the fluid is dirty and smells burnt, then it needs to be changed.

    5

    Turn off your Chevy and let it cool down for a couple of hours.

    6

    Shimmy yourself under your Chevy and find the transmission. The transmission is connected right behind the engine. Use the light to find any leaks, broken wires or parts that have come loose.

Rabu, 19 Januari 2011

How to Test the Mass Air Flow Sensor on a 1993 Explorer

The MAF sensor is one of the interesting sensors on your truck, in that it -- like the oxygen sensor -- uses heat as a means to indirectly measure airflow or oxygen content. All wires have a certain amount of resistance, as measured in ohms. The more ohms of resistance the wire has, the hotter it gets when electricity passes through. The resistance in your MAF sensor wire causes it to rise in temperature when it receives a certain voltage, and air flowing over the wire cools it down. Testing the MAF sensor output is simple once you've established that it's getting the proper voltage.

Instructions

    1

    Locate the MAF sensor in-line between the airbox and the engine and unplug the sensor harness from it. Orient yourself toward the plug on the sensor so that the single locking tab is on "top." Do not disconnect the sensor yet.

    2

    Designate the wires. The wires, from left to right, are the VPWR wire to the computer or power relay, the Ground (GND), the MAF Return (RTN), and the MAF Signal (MAF). The chassis-side harness wires should be solid red for the VPWR, black and light green for the GND, tan and light brown for the RTN, and orange and light brown for the MAF.

    3

    Turn your key to the "on" position without starting the truck. With your digital multimeter, measure the voltage between the VPWR wire on the chassis-side harness and the truck's negative battery terminal. It should read at least 10.5 volts. If it doesn't, your problem is in the power supply from the computer.

    4

    With the key still on and the sensor disconnected, measure the voltage between the VPWR terminal and the GND terminal; it should read 10.5 volts. If not, you have an interruption in the sensor's chassis-side ground. Once you've established that your MAF sensor is getting power, reconnect the harness to the sensor.

    5

    Start the engine and allow it to warm up and reach operating temperature. Poke your red DMM probe into the MAF wire -- the orange and light-brown one -- and the black needle probe into the GND wire. You should get a reading of between 0.36 and 1.50 volts. The voltage should be relatively steady; if it rapidly jumps up and down by 0.50 volt or more or goes outside the specified range, replace the MAF sensor.

    6

    Repeat this test but have an assistant lightly tap on the MAF sensor to simulate shock loading to the sensor. Tapping on the top of the sensor with the handle-end of a good-sized screwdriver should deliver the appropriate shock. If the sensor voltage rises or falls more than 0.4 volt when you administer the tap, something's loose or broken in the sensor and it needs to be replaced.

How to Troubleshoot Code 0405 in Explorer

How to Troubleshoot Code 0405 in Explorer

The engine and drivetrain systems in today's complex vehicles, including the Ford Explorer, operate under the constant watch of the vehicles' on-board computer monitoring system. This system relates to the driver or mechanic instant feedback pertaining to the function of all power and drive systems. It does this by presenting diagnostic information in the form of a code. Each code identifies a particular component or system that is not functioning properly. A code of 0405 indicates the circuit used to supply the EGR system is operating under a condition lower than optimal voltage.

Instructions

    1

    Raise the hood of your Explorer, and locate the EGR valve. It is bolted to the top of the intake manifold, under the air cleaner.

    2

    Remove the electrical connector from the EGR valve by pulling it off with your hand. Turn the ignition key to the "on" position, but do not start the engine.

    3

    Test the connector pins with the voltage meter. One of the pins should give a reading of five volts on the voltage meter. If no connector pin is reading at five volts, but 12 volts are present in one pin, suspect a short in the wire. If the reading shows no voltage at any pin, connect a test light to the connector pins, and bend and flex the connector and wires attached to it. If the test light operates, damage has been done to the connector or its wires.

Reasons for Engine Oil Pump Failures

Reasons for Engine Oil Pump Failures

The oil pump in an engine is responsible for keeping the engine oil flowing so it can lubricate the motor. A faulty pump can lead to an engine that is running metal component on metal component, generating heat and pressure until a component warps, breaks or otherwise malfunctions. Oil pumps can fail for a variety of reasons, and must be repaired promptly.

Debris

    Oil pumps have a screen over the pick up tubes that is designed to keep large particles of debris from being sucked out of the crankcase and into the oil pump. However, the screen does not always stop smaller pieces of dirt and debris from making it into the oil pump. Over time, dirt and debris will build up in the oil pump and cause wear and tear to the pump. Wear due to debris will cause problems with the pump and can ultimately cause it to clog or otherwise fail.

Oil Sludge

    Failing to regularly change your oil will lead to sludge developing in your engine. When your oil pump attempts to pump oil sludge through your engine, it has to work much harder than it should and will clog or wear out sooner than it should. This is one of the many reasons you should change your car's oil regularly.

Blow-By

    If the pistons and rings are worn on your engine and causing a large amount of blow-by, your pump may wear at an accelerated rate. Pumping and filtering the oil blow-by out of the engine can wear out your pump or cause it to break.

Troubleshooting a Gasoline Auto Engine

Troubleshooting a Gasoline Auto Engine

Today's automobile engines are made up of many different parts, systems and components. Because of the complexity of the engine, it can often be difficult to determine what is wrong with your car. One method used to troubleshoot a gasoline automobile engine is to listen to the noises the vehicle makes as you drive it. Certain parts within your engine will cause a particular noise and help you locate what repairs need to be made.

Instructions

    1

    Inspect the battery of the vehicle when the engine makes a loud clicking noise as you drive. The battery could be faulty or discharged and should be replaced. If the battery is still working properly, check the starter and see if it is faulty. Finally, look at the flywheel that connects the transmission to the engine and ensure that it is functioning properly.

    2

    Find the engine's transmission mount when the engine makes a chirping noise as you drive. The mount could be worn, broken, loose or damaged and should be replaced.

    3

    Examine the air filter inside the engine when the vehicle's idle is rough or erratic while the engine is still cold. The air filter could be clogged or dirty. You should also find the spark plugs at the top of the engine and check to see if they are incorrectly gapped (the space between the electrodes is incorrect) or damaged. Look also at the engine's wire set and see if the spark plug wires are improperly connected to the spark plugs, worn or otherwise damaged.

    4

    Check the timing of the vehicle's engine if you hear a pinging noise as you drive. If the ignition timing is set incorrectly, have a qualified mechanic adjust it for you. If the ignition timing is properly set, look at the spark plugs to see if they are gapped correctly and whether they are worn or damaged. If the pinging noise is more prevalent when you accelerate the car, check the crankshaft, knock sensor, heater control valve, exhaust gas recirculation (EGR) position sensor and timing components to see if any of these parts are damaged, worn or in need of repair.

    5

    Inspect the air filter and fuel filter when your engine is hard to start. Both of these filters could be clogged or dirty. You should also check the positive crankcase ventilation (PCV) valve to see if it is clogged and the choke thermostat to determine if it has become stuck or is not functioning properly. The EGR valve, carburetor and PCV hoses should also be examined.

Senin, 17 Januari 2011

How to Know Whether Shocks Need Replacing

How to Know Whether Shocks Need Replacing

If your car is bouncing more than it should and isn't handling bumps and curves quite like it used to, the time may have arrived to have the shocks checked and replaced. According to the Motorist Assurance Program (MAP) "shock and strut replacement should not depend on a vehicle's mileage or whether the shock absorbers or struts failed a bounce test." Replacing shocks is just as important as changing your oil, but some drivers are apt to overlook the signs and run into serious trouble as a result.

Instructions

    1

    Measure the height of all four corners of your car with a tape measure, and compare them. A difference of 1/2 inch or more from one side to the other may mean sagging springs or a worn suspension system. Consult your owner's manual to find out the correct ride height for your car.

    2

    Take your car for a test drive. Feel how your car rides on a rough or rocky road and how it handles bumps. Take it for a spin in rain and snow, and note any differences in handling. If your car leans to one side when making a turn, squats in the rear after you put your foot on the gas, nose dives when braking hard and fast,or bottoms out when flying over a bump, have your shocks replaced.

    3

    Perform a bounce test on your car. Standing in front your car, rock the bumper up and down a couple of times. (You may need two people to perform this test.) If your car gyrates two or more times after you let go, you may need to replace your shocks.

    4

    Check your tires and suspension system parts---ball joints, springs, constant velocity (CV) joints and steering linkage---for signs of wear. Look for punctured piston rods, leaks and dents on shock housings and wear and tear on rubber mounting bushings. Problems with any of these parts may point to bad shocks.

Reasons for Blown Fuses for Windshield Wipers & Washers

Reasons for Blown Fuses for Windshield Wipers & Washers

It can be frustrating when your vehicle keeps blowing your windshield wiper and washer fuses. Several reasons exist for a blown fuse for windshield wipers and washers.

Current

    The windshield wiper or washer motor could be drawing too much current. To see if this is the problem, disconnect the wiper motor for a little while. If the fuse doesn't blow, the motor is drawing too much current.

Interference

    Another reason for a blown fuse for your windshield wipers and washers may be debris or ice built up around the wipers. Look around the wipers and see if there is anything that could be interfering with the arm movement, and remove it. Test to see if this was causing the problem.

Warning

    If you have a fuse that keeps blowing, do not replace it with a larger, higher amp fuse. The size of the fuse is predetermined to help protect the circuit. If a larger amp fuse is placed where it is not needed, it will not stop the flow of the current when necessary.

Warning Signs That Your Automatic Transmission Is Going Out

Warning Signs That Your Automatic Transmission Is Going Out

Automatic transmissions are very popular on U.S. roadways. Though some drivers prefer manual transmission, many find it easier to maneuver their car on city streets with automatic transmission. The transmission is a machine inside the vehicle, which means it is susceptible to breaking down like any other part of the vehicle. This is why its important for drivers to know the warning signs that the automatic transmission is going out.

Car Jerks

    If you feel the car jerk, it may be the transmission
    If you feel the car jerk, it may be the transmission

    One of the most notable signs that the automatic transmission in a vehicle is going out is when the car jerks while shifting gears. Drivers often feel the jerk as it pitches them slightly forward as the car shifts when driving down the road. This jerk becomes more frequent and pronounced when it occurs as the automatic transmission has a hard time shifting into the correct gear.

Vehicle Winds Up Longer

    Feeling your car taking longer to shift is another sign
    Feeling your car taking longer to shift is another sign

    Each vehicle has a rhythm to its gear shifting which makes it possible for most people to predict when a car is going to change to a higher gear as they accelerate. Often a person feels the car winding up until it reaches a specific number of revolutions per minute (RPM) and shifts. When the automatic transmission is going out, cars spend more time winding up to a higher RPM when accelerating before they shift to a higher gear.

Losing Transmission Fluid

    Check for oil leaks and low fluid
    Check for oil leaks and low fluid

    Its important to periodically check your transmission fluid and add more fluid as needed to keep your transmission in good shape and preserve it for as long as possible. However if your vehicle starts requiring a significant amount of transmission fluid, this may be a sign your automatic transmission is going out. If this is the case, first check to make sure that there isnt a leak in the hose or the reservoir for the fluid. If this isnt a leak, the chances are your automatic transmission is going out. Your vehicle is using more fluid to try and compensate for the additional grinding and jerking of the gears inside your transmission.

Hot Smell

    That buring smell should be checked out by a mechanic
    That buring smell should be checked out by a mechanic

    Another warning sign about your automatic transmission is a hot, burning smell after driving the vehicle. The metal gears in your transmission have trouble shifting as they grind against each other. This creates a burning smell you may notice even after driving only short distances. This smell may be a result of something else wrong with your vehicle though, so its important to have your vehicle checked out by a mechanic.

Minggu, 16 Januari 2011

Troubleshooting a 2000 Grand AM Passenger Door Power Lock That Won't Work

The power door lock system on a 2000 Pontiac Grand Am consists of a door lock switch on each door, including a master switch on the driver's side door, a fuse and relay, a door lock solenoid, a link rod and wiring. The power door locks are controlled by the switch on each door panel, which activates a bi-directional solenoid attached to a link rod. A non-operational lock can be diagnosed in a few minutes in order to find the component within the system that has failed.

Instructions

    1

    Inspect the power door lock fuse. Pull the cover from the fuse box on the left end of the dashboard. Find the appropriate fuse using the diagram on the inside the fuse box cover. Pull the fuse with needle-nose pliers and inspect the inside of the fuse for any signs of damage or wear. If the fuse is damaged or worn, it needs to be replaced.

    2

    Temporarily replace the door lock relay. Pull the cover off of the relay box inside the engine compartment, near the firewall on the driver's side. Locate the relay for the power door locks using the diagram on the inside of the relay box cover. Temporarily pull a similar relay from another location and use it in the power door lock relay spot. If the temporary relay fixes the power door lock, the original power door lock relay is faulty and needs to be replaced.

    3

    Press the master door lock switch on the driver's side door panel. Listen at each door panel for the clicking sound, which indicates the solenoid has been activated by the switch. If all of the solenoids are active, continue diagnosing the switch and wiring with the following steps. If the solenoid does not activate from the master power door lock switch but the others do, replace the passenger's side door lock solenoid.

    4

    Press the door lock switch and listen for a faint clicking sound. If no sound is heard, test the voltage at the switch with a test light, attaching the grounded test light to the wiring on the underside of the switch. If voltage is not present, inspect the wiring running from the fuse box to the switch for damage and replace any damaged sections. If no sound is heard and the test lights shows voltage on the door lock switch, replace the door lock switch, as the lock switch no longer has continuity.

Sabtu, 15 Januari 2011

How to Troubleshoot a Chevrolet 350 Vortex 1998 Pickup

The 1998 Chevrolet Silverado came equipped with a 5.0-liter eight-cylinder engine. The truck also included many different standard features such as cruise control, a chrome step bumper, tinted glass, a lighted entry system, power windows, power door locks, daytime running lights, cloth seating, power exterior mirrors, four-wheel anti-lock brakes and driver and passenger front airbags. Because the Silverado has a complex make up of various parts, systems and components it can be difficult to find a problem with the vehicle. Two ways to troubleshoot your Silverado are to look at manufacturer recall data and to apply general troubleshooting strategies.

Instructions

    1

    Examine the oil filter installed in the engine of the Silverado when you see oil leaking underneath the vehicle. Certain oil filters that were built for the truck were not manufactured properly and the filters become more pliable under high temperatures and pressures. If the filter bends or moves too much, the filter will not have an adequate seal around the oil lines inside the engine and oil will leak. If the oil comes into contact with an ignition source, a fire could erupt inside the engine compartment of the Silverado. Replace the filter with one that was manufactured properly to avoid this result.

    2

    Inspect the fuel filter installed in the Silverado if the truck is leaking gasoline below the engine block. Some brands of fuel filters were not manufactured to the proper specifications. Consequently, the O-ring that connects the fuel filter to the fuel lines inside the Silverado's engine may not seal correctly. This will allow gasoline to leak down through the engine and possibly start a fire if the gasoline gets hot enough or comes into contact with an ignition source. You should change the fuel filter if you believe the O-ring is faulty and allowing gasoline to leak out.

    3

    Look at the oxygen sensor if your truck's exhaust emits a rotten egg or sulfur-like smell while the engine is idling or you are driving. The sensor may be damaged or faulty and in need of repair. Make sure that the timing specifications of your engine's cylinders are proper and reset them as needed. The catalytic converter could be clogged or has stopped working as well. You should also inspect the PCV valve to see if it has become clogged and the carburetor to make sure it isn't dirty or improperly functioning. One or more of your PCV hoses might also be collapsed or clogged.

How to Troubleshoot Marine Motors

How to Troubleshoot Marine Motors

Troubleshooting marine motors can be likened to diagnosing problems with an automotive engine, with some additional concerns and extra systems. The typical marine engine, whether outboard, inboard or stern drive, sustains much more stress than automobile engines. Marine engines do not have the luxury of coasting and suffer constant load and torque pressures. Becoming stranded on a boat far from shore can be a major inconvenience, as well as dangerous for the pilot and crew. Troubleshooting a marine engine requires a patient process of elimination to find a failing component or system, as well as a knowledge of how that component or system works.

Instructions

    1

    Set a multimeter for DC volts on the lower scale and attach the red meter probe to the red (positive) lead on the battery terminal. Attach the negative meter probe to the negative (black) terminal on the battery. The meter should read 12.5 volts or more, which is the standing voltage. Any volt reading less indicates a battery in the state of discharge. If the engine runs, keep the meter hooked up to the terminals and bring the engine to a fast idle. Turn on all your accessories. The reading should indicate 13.5 to 14.4 charging volts. Any reading less indicates a problem with the alternator or regulator.

    2

    Unsnap the engine cowl and remove the plug wire or wires. Inspect the plug for cracks and disconnection at the fittings. Use a socket and wrench to remove the spark plug and check the electrode for a light brown or tan coloration -- a normal indicator of a good plug. Black, wet or white electrodes will indicate overly rich, flooded or an overheated spark plug. Connect the plug wire to the spark plug and set it on the engine block, close to a ground source. If the engine will start, turn it over and look for a spark jump from the plug to the ground. No spark indicates a problem with the coil or ignition system.

    3

    Remove the spark plug (or plugs) with a socket and wrench. Screw in a compression gauge adapter hose into the spark plug threads. Disconnect the coil wire completely and set the transmission selector in neutral. Turn the engine over six to eight times with the starter key and read the gauge. Proper compression for a motor's cylinder should range between 115 and 125 pounds per square inch (psi) for a high compression engine. Some lower compression engines might require only 80 to 100 psi. Check your repair manual for the correct psi range. Cylinders which differ by 10 psi or more indicate a compression problem with the valves, rings or head gasket.

    4

    Use a fuel filter wrench to remove the fuel-water separator from your engine. Unscrew the canister counterclockwise and inspect the interior. There should be no water inside the canister. Pour the contents out into a clear glass jar and look for water and oil separation level. If water exists, it means water has entered the fuel system, possibly causing a vapor lock, or cylinder lock. Refill the separator canister with fresh fuel from your gas tank, via the primer bulb and hose, and then screw it back onto the engine by hand.

    5

    Clear the exhaust ports on the lower motor unit of seaweed, silt, plastic and other debris, if experiencing an overheating problem. For stern drive and outboard motors, the exhaust water should be warm to the touch and exiting the exhaust ports in steady streams or sporadic bursts. For an enclosed fresh water cooling system, make sure the radiator level is up to maximum, and that the thermostat opens properly after the motor reaches normal operating temperature. Check the wet exhaust manifolds for leaks, if so equipped, and tighten any loose bolts with a socket and wrench. No flow from the exhaust ports on the lower unit indicates a wedged or broken water pump impeller.

    6

    Check the air intake filter and flame arrestor box for clogs of rust and debris. Remove the flame arrestor with a socket and wrench and clean the inside of all foreign matter. If equipped with a cartridge air filter or element, remove the filter and attempt to start the motor. If the motor runs, the air filter is clogged.

    7

    Check the gas tank for an appropriate level of fuel. The fuel should be fresh, with no bitter or stale odor. Old fuel will deposit gum and varnish in the carburetor jets, disallowing motor start-up or proper running. Remove all in-line fuel filters with a screwdriver and blow through both ends of the filter to insure the screen elements are free and clear of obstructions.

    8

    Place one end of a jumper wire on the "Bat" terminal on the starter solenoid and the other end of the wire on the small, thin solenoid terminal. Place the ignition key in the "On" position. If the starter spins and engages the engine, whereas it did not before, the solenoid is defective, which will cause a no-start condition.

When a Thermostat Goes Bad, Does the AC Still Work in the Car?

When a Thermostat Goes Bad, Does the AC Still Work in the Car?

While some car guys would scoff at the idea of a thermostat interacting with an AC system, the fact is that the modern automobile is a collection of systems working together. While the AC and cooling system are mechanically independent, that doesn't necessarily mean that a malfunction in one can't affect the other.

How AC Works

    An air conditioning system is basically a series of heat exchangers, or radiators, with a compressor somewhere in the middle. All fluids on Earth -- including air and AC refrigerant -- contain a certain amount of energy in the form of heat. When you squeeze the fluid's molecules closer together, you increase the fluid's temperature. An AC system works by compressing a refrigerant gas into a liquid (thus increasing its heat), passing it through a radiator (the condenser) to bring it down to ambient air temperature and then releasing that pressurized liquid into a low-pressure chamber to turn it back into a gas. That super-chilled gas cools another heat exchanger (the evaporator); air passing through the evaporator picks up some of its coolness, flows into your car and keeps your ice cream from melting.

How a Thermostat Works

    Car engines work best when kept at a certain temperature, typically between 160 and 240 degrees Fahrenheit. All metals expand as they heat, and different metals -- and different thicknesses of metals -- expand at different rates and by different amounts. The average engine maintains internal component clearances often less than 1/100th of an inch, which doesn't leave much room for metal expansion. Engineers must design an engine with the clearances at a specific temperature in mind, and that's usually somewhere around the boiling point of its coolant. A thermostat is a valve in the cooling system that closes when coolant temperatures are low, in order to recycle coolant through the motor and bring it up to the ideal temperature. When coolant temperature rises to the engine's ideal, the thermostat valve opens to send coolant through the radiator in order to maintain that temperature.

Normal Interaction

    Under most circumstances, a bad thermostat will not have any effect whatsoever on the air conditioning system. The AC system is a completely separate entity; the only connection it has to the engine is at the compressor pulley, which derives its power from the crankshaft. Other than that, the AC system could care less what the engine is doing. The heater, however, is a different story. A car's heater core is like a second radiator. When you turn the heater on, a valve opens in the heater core line and allows hot engine coolant to flow into the core. Cabin air blows through the hot core and into your car to warm the occupants. A stuck-open thermostat will constantly send coolant through the radiator to cool, meaning that the coolant -- and thus the heater -- may never reach its full operating temperature.

Computer Controls

    While engine cooling systems and air conditioning systems are mechanically separate, computer controls can act as a link between between the two. Air conditioning compressors put a fair amount of stress on the engine, generally sucking up between 10 and 15 horsepower when active. If you're a physics geek interested in such things, that's an extra 424 to 636 British Thermal Units of heat energy per minute that the cooling system must dispose of in order to maintain equilibrium. Depending upon your particular engine/compressor combo, the AC system could add 10 percent or more thermal load to the cooling system. If your thermostat sticks closed and the engine begins to overheat, your car's computer may well shut the AC compressor down in a last-ditch effort to reduce the thermal load on the system. Of course, if your car's engine overheats by that much, then odds are that you've got bigger problems than liquefied Butter Pecan.