Sabtu, 28 Februari 2009

How to Troubleshoot a BMW Transmission

How to Troubleshoot a BMW Transmission

The BMW is a very popular European car known for efficient gas mileage and reliability with minimal servicing. There will come a time in the life of the car where you may need to know how to troubleshoot a BMW transmission. This can be done with a minimal amount of free time in the convenience of your own home. You won't need any special tools for these operations and this will allow you to be able to assess the problem before approaching a mechanic.

Instructions

    1

    Turn on the car engine and leave it running for around 15 minutes.

    2

    Lift up the hood of the car. Locate a looped handle for the transmission fluid in the back of the car engine and remove it all of the way out.

    3

    Check that the fluid is red and not burnt or a brownish-red color. In the case of the latter issues, you will need to have the transmission checked and the fluid flushed.

    4

    Examine the level of the transmission fluid on the bottom portion of the dipstick. If the fluid is not between the highest and lowest marks on the dipstick marker, add more fluid until the proper level is achieved.

    5

    Place the car in gear and listen for a grinding sound. Check that it is not too hard to place the car in gear. If either of these is the case, you will need to take the car to a mechanic because there may be chipped gears or damaged synchronizers.

What Are the Functions of the Emission Control Valve in Trucks?

Starting in the 1990s, the federal government began requiring new vehicles to integrate sensors and technology to reduce emissions from combustion. These requirements included a number of new controls, valves and sensors that track engine performance. The emission control valve is one of those features.

Emission Control Systems

    Cars manufactured since the federal mandate include an evaporative emission control system. This series of channels and sensors control gas fumes from escaping into the atmosphere. The emission control valve opens the system to venting so gas can lower in the tank as it gets used but closes to keep it pressurized.

Code Signals

    When the emission control valve in a truck or car doesn't work correctly, the fault will typically be translated to the vehicle's on-board diagnostic computer as a code P1443 or P0446. This code can cover a number of other emission control system faults, so it is not unique to the valve function.

Diagnosing the Issue

    The best way to figure out if an emission control valve is faulty is to connect an on-board diagnostics (OBD)-II scanner to the car's computer and read the codes. The scanner will pull down the error codes that signal the valve malfunction. Then, a mechanic can make repairs.

How to Check the Fuel Pump Pressure of a 2001 Prizm

One of the vehicles that emerged from the Chevrolet and Geo partnership was the Geo-Chevrolet Prizm. Introduced in 1989, the Geo Prizm became the Chevrolet Prizm from 1998 to 2002. The 2001 Chevrolet Prizm was equipped with a 1.8-liter fuel injected in-line four-cylinder engine. The fuel pressure on the 2001 Prizm can be tested from inside the engine compartment, somewhat easily. The 2001 Prizm has a Schrader valve similar to the ones on your tire valve stems that allows you to test the fuel pressure.

Instructions

    1

    Open the hood on the Prizm and set the hood prop. Locate the small green cap on the top driver's side of the engine. Remove the green cap that covers the fuel pressure testing port.

    2

    Wrap a small screwdriver in a rag. Insert the tip of the wrapped screwdriver into the tester port. Depress the pin in the center of the port slightly to release the fuel pressure in the fuel system. Allow the rag to soak up any fuel expelled from the tester port during this procedure.

    3

    Install a fuel pressure gauge onto the tester port. Ask your assistant to turn the ignition key to the "Start" position. The fuel pump will activate immediately and prime the fuel lines if the powertrain control module or PCM is working properly. If no fuel pressure appears on the tester gauge, inspect and test the PCM. Fuel pressure for the 2001 Prizm should be between 44 and 50 pounds per square inch.

Kamis, 26 Februari 2009

Why Is My Catalytic Converter Glowing Red?

Why Is My Catalytic Converter Glowing Red?

Catalytic converters are designed to heat toxic gas molecules until their bonds break and they fall apart. However, certain malfunctions can overheat the converter and cause it to glow red. This situation is dangerous and can lead to a car fire.

Converter Construction

    Modern converters utilize two honeycomb-like ceramic blocks containing thousands of tiny passages. The passages of the first honeycomb are coated with platinum and rhodium, which pulls nitrogen away from oxides of nitrogen and re-forms it into nitrogen gas and oxygen. The oxygen gets trapped in the platinum/palladium material inside the second honeycomb, where it combines with unburned fuel in a combustion event that produces heat and carbon dioxide.

Rich Mixtures

    The primary cause of converter overheating is an over-abundance of fuel in the exhaust stream. The fuel enters the second ceramic block and burns there, creating excess heat. As temperatures soar to over 1,500 degrees, the ceramic matrix cracks and collapses on itself. This collapse blocks the exhaust, storing even more heat and causing further overheating. This results in a self-sustaining cascade effect of overheating known as "converter melt-down."

Rich Condition Causes

    Several situations can cause your engine to run "rich" and introduce excess fuel into the converter. These situations include an oxygen sensor malfunction, engine misfire, improper choke or idle air control (IAC) valve operation, fuel injector leakage and computer malfunction.

Rabu, 25 Februari 2009

How to Read Codes on a 2008 Yukon

As of 1996, diagnostics for U.S.-sold vehicles changed. The Environmental Protection Agency passed a law requiring use of OBD-II diagnostic systems for all vehicles. Before 1996, repair facilities had to keep many different computers to diagnose all of the vehicles on the road. With the new system, all makes and models use the same diagnostic system, but the protocols do vary. This means that instead of buying complete computers or scanners, the shops now only need to update software. The 2008 GMC Yukon falls within the OBD-II system and any basic scanner can read the codes.

Instructions

    1

    Open the driver's side door.

    2

    Trace the steering column downward and toward the underside of the dashboard.

    3

    Look under the dashboard on the driver's side of the steering column and locate the OBD-II scanner port. It is a female receptical and it is in the same shape as the plug on your scanner.

    4

    Plug the OBD-II scanner into the OBD-II port on the vehicle and turn the ignition to the run position, but do not start the vehicle.

    5

    Turn the scanner on and follow the scanner instructions on reading codes. All scanners have different procedures for this step.

    6

    Read the code that is displayed on the LCD screen---it will have a "P" followed by four numbers.

Why Does My Car Accelerate Slowly?

Why Does My Car Accelerate Slowly?

When a car accelerates slowly, something is affecting the correct mixture of oxygen and fuel that allows your engine to operate at peak efficiency. A number of faulty parts can cause this hesitation.

Fuel System

    A plugged fuel filter, air filter or fuel pump can cause your car to accelerate slowly. A damaged or dirty carburetor -- or dirty fuel injectors that aren't properly mixing the fuel with air -- might contribute to slow acceleration.

Electrical System

    Faulty spark plugs might fail to ignite your car's mixture of oxygen and fuel; this can cause your car to accelerate slowly. Worn or damaged spark plug wires interfere with spark plug ignition.

Sensors

    Dirty or worn computer sensors in the engine might cause delayed or slow acceleration. Sensors functioning improperly fail to detect and send correct information to your vehicle's various systems.

Exhaust System

    A catalytic converter removes harmful emissions from the tailpipe. These emissions back up and interfere with the flow of fuel and air when the converter is plugged or damaged.

How to Test an ABS Speed Sensor

How to Test an ABS Speed Sensor

The primary function of sensors in automobiles is to keep the on-board computer (OBC) or electronic control module (ECM) informed of what is going on with the automobile at any given moment. The anti-locking braking system (ABS) speed sensor is a magnet that picks up on a cogged ring that rests on the spindles of the wheel. The ABS speed sensor lets the computer know at any given moment how fast the automobile's wheels are rotating.

Instructions

    1

    Elevate the rear of the vehicle in a secure position with a car jack, and place it on jack stands. Place wheel blocks around the front tires. Remove the rear tires to test the ABS speed sensors.

    2

    Locate where the engine's electrical wiring harness meets the sensor's electrical wiring harness. This is generally in proximity and secured around the strut housing in the wheel well in the front and the shocks in the rear.

    3

    Remove the sensor from its position using a quarter-inch ratchet with an 8- to 10-mm socket, which is generally located by the heat shield on the caliper.

    4

    Examine the end of the sensor. If it looks like a big fur ball at the end, then too much contamination is disrupting the sensor.

    5

    Spray the sensor with brake cleaner and wipe with the rag to remove contamination. Contamination on the sensor can send erroneous signals to the computer.

    6

    Disconnect the engine harness from the sensor harness. Set the voltage meter to "Ohms," and connect the positive and negative terminals of the voltage meter to the input and output on the sensor. If the voltage meter registers as infinity, then the sensor has failed and needs to be replaced.

    7

    Switch the meter back to "Volts," if you do not see an infinity in the ohms setting. If the voltage meter reads above 5 volts, it is starting to fail and can cause intermittent problems. If the voltage meter reads below 5 volts, check the knock sensor for corrosion and check the electrical connections leading to the knock sensor.

Selasa, 24 Februari 2009

How to Determine If Struts Need to Be Replaced

How to Determine If Struts Need to Be Replaced

A vehicle's shocks and struts are more than just about ensuring a smooth ride -- they are also an important part of the steering and handling mechanism. Damaged shocks or struts will affect the vehicle's ride, and can affect its control on the road. Before replacing a vehicle's shocks and struts, look for some common signs.

Instructions

    1

    Pay attention to whether the vehicle's ride seems unusually bumpy or stiff. That is a strong indicator that the shocks and struts need replacing.

    2

    Notice how the vehicle steers and turns corners while driving. If it is making unusual noises when it hits rough terrain, seems to sway while turning corners or doesn't steer as responsively as it once did, it may point to bad shocks and struts.

    3

    Measure the vehicle's height at each corner of the vehicle. If one corner or side of the car is notably lower than the others, the shocks and struts may have broken and need to be replaced.

    4

    Perform a bounce test on the vehicle. A bounce test is when you use the bumper to physically bounce the vehicle once or twice and then release it. If the vehicle keeps bouncing more than once or twice after it has been released, then it has weak shocks or struts.

    5

    Physically examine the shocks and struts. Look to see if the shock or strut piston rod have been damaged or bent. Check for corrosion and oil leaks. If you are still uncertain as to whether the vehicle's shocks and struts need to be replaced, take it to a mechanic for a professional determination.

Symptoms of Ignition-Control Module Malfunction

Symptoms of Ignition-Control Module Malfunction

The ignition-control module is an essential part of a vehicle's ignition system. It works in conjunction with other ignition-system parts, such as the spark plugs and ignition coil, to start a vehicle and maintain power. If the ignition-control module malfunctions, it will not properly initiate the spark that causes an engine to start up, and there are specific symptoms that are indicative of a faulty one.

Overheating

    When an ignition-control module malfunctions, a vehicle can overheat. The first sign of this is when the temperature gauge--located on the dashboard--moves above the normal temperature range, indicating extremely-high engine temperatures. This will cause the vehicle to often stall and lose power suddenly. After the engine cools down, the vehicle may start, but will eventually overheat and stop again. This overheating cycle will continue, causing the engine to fail permanently. So, it's advisable to not drive the vehicle until the ignition module is analyzed.

Acceleration Problems

    A faulty ignition module can cause a vehicle to experience acceleration problems. The vehicle may hesitate or vibrate when the gas pedal is pressed. Also, there may be dragging or slowing down when switching from a slower to higher speed.

Damage

    Damage is often visible on an ignition-control module that needs replacing. Check the module, which is usually located inside an engine compartment or mounted on the engine in the distributor. Inspect it, as well as the bolts around it, for cracks and extensive rust or wear. If there are any visible defects, the module is probably faulty. Also, a working module should have a greasy film on the back to protect it from an engine's high temperatures. If this greasy substance is not present, the module may need replacing.

No Power

    If a faulty ignition module is not diagnosed and replaced, it may eventually cause a vehicle to permanently lose power. The engine will often turn over several times before starting, only to cutoff again. Repeatedly trying to start the engine may cause it to produce clicking sounds--which indicates the absence of a spark in the ignition system. That intensifies when the ignition switch is held in the start position.

How to Read Electrical Symbols for Automobiles

On an automotive wiring diagram, symbols are used to convey the locations and types of the components used in the car's wiring. These symbols can be confusing unless you can learn how to read them. Most automotive wiring diagrams use the same standard electrical symbols to show the location of basic components such as switches and batteries. Other symbols denote wire size and color, or serve as an abbreviation for a common electrical term.

Instructions

Basic Symbols

    1

    Locate a switch by finding an arrow that interrupts the straight line of a wire by angling away from the line. This arrow points to a box. A dotted line curves from this box back to the wire to show that a circuit is completed when the switch is shut.

    2

    Find a battery by locating a series of four lines perpendicular to the wiring. These lines alternate a long line with a short line. The wiring continues after this set of lines.

    3

    To find a resistor, look for a line that zigzags back and forth with three peaks on each side of the line.

    4

    A ground is located by looking for the wire that ends at a dot with the code "G100" next to it. The dot appears to be sitting on three small lines that get gradually shorter.

Wire Size, Color and Connection

    5

    Find the diameter of the wire by locating a number placed next to the wire. This number generally precedes a code for the color of the wire.

    6

    Locate the color of the wire by finding the three letter code for the color printed near the wire marking on the diagram. An example of this code is "BLK" for black.

    7

    Follow a wire until it meets another wire. A connection is designated by a dot. If the wires cross and are not connected, one wire will appear to bump up over the other wire and no dot is printed.

Abbreviations

    8

    The amperage of a wiring circuit is found by locating the letter "A" printed beside a number.

    9

    Find the pass-through grommet by locating the symbol "P100."

    10

    Find the symbol "C1." This symbol stands for the terminal connector identification.

    11

    Locate the symbol "B+." This also designates a battery connection.

Senin, 23 Februari 2009

How to Know If a Crankshaft Position Sensor Is Bad?

Crankshaft position sensors are essentially super-accurate tachometers, responsible not only for telling the computer how fast the engine spins, but also exactly where the crankshaft is positioned in its rotation. The computer uses this information to determine when to inject fuel or trigger the spark plugs; because of this, a bad CPS can manifest in any number of systems. Your best bet is to skip the guess-work altogether and test the sensor directly.

Instructions

    1

    Test drive the vehicle to get an idea as to what's going on with the engine. A lightly-malfunctioning CPS will cause a slight loss in power and fuel economy, as well as some intermittent stuttering under acceleration. A badly-worn CPS will cause multiple misfires, bucking and surging, and will ultimately manifest a complete refusal to start or idle.

    2

    Go to your local Advance, Pep Boys, O'Reilly, Jiffy Lube, Napa or other large auto parts chain store and have them read your vehicle's computer codes. A bad CPS will always trigger a "Check engine" light, and any chain parts store will have a scanner available to read the codes stored in the vehicle's computer. Some stores charge for this service and others do not.

    3

    Locate the CPS. You'll need a repair manual to get the CPS sensor's voltage anyway, so refer to the reference material to find your CPS. Follow the wiring harness connected to the sensor to a location on top of the engine where you can access it while cranking the motor. Unplug the wiring harnesses going into your ignition coils to keep the car from starting while you crank it over.

    4

    Set your digital multimeter to read in AC volts and plug the needle-probe wires into the meter. Poke the negative (black) needle probe into the darker of the two wires coming out of the CPS; plug the red needle probe into the lighter of the two wires. Turn the multimeter on and have an assistant crank the engine as though attempting to start it.

    5

    Observe the reading on the digital multimeter and compare it to your reference material. The reading should fluctuate by the readings specified in your reference material; typical output will range from 0.2 volts on the low reading to 1.5 volts on the high side. If the oscillations are irregular or you don't get a voltage reading, then the sensor is bad.

Minggu, 22 Februari 2009

My Honda Won't Turn Over & Is Not Starting

My Honda Won't Turn Over & Is Not Starting

You get up in the morning to go to work, put the key in the ignition, listening for the whirr of the engine, and nothing. Your Honda will not turn over and start. The most likely cause is a problem in the starting electrical system. Troubleshooting requires that you begin with the battery and move on to measuring voltage in the system. Successful troubleshooting is possible with a digital voltmeter and a little time.

Instructions

    1
    Use a small wire brush to clean the battery connections.
    Use a small wire brush to clean the battery connections.

    Verify that the battery terminals and connections are tight and free of corrosion, oil, dirt and debris. If corrosion appears on the battery terminals and connectors, clean them with baking soda. Detach the negative cable from the negative battery post. Secure the cable so it will not contact the negative battery terminal. Detach the positive battery cable and secure it. Spread baking soda on the corroded terminal. Dip the wire brush or old toothbrush into a cup of water and clean the terminal. If needed, continue with the battery cable connectors. After you have removed the corrosion, reconnect the positive battery cable, and then connect the negative battery cable.

    2
    Use a digital voltmeter to measure the troubleshoot the electrical system.
    Use a digital voltmeter to measure the troubleshoot the electrical system.

    Verify that the chassis ground connection on the frame is clean and free of corrosion, oil, dirt and debris. Clean the chassis ground connection with baking soda if the connection has corroded. Use your digital voltmeter to measure the resistance from the minus battery terminal to chassis ground. The resistance should be less than anohm. If the resistance is greater than that, there is high resistance or open circuit in the cable. Replace the cable.

    3

    Set the voltmeter to read DC volts and measure the voltage from the positive battery terminal to chassis ground. The voltage should be approximately 12.6 volts. If the voltage is less than ten volts, place the battery on a battery charger.

    4

    Measure the voltage across the starter solenoid. Set the digital voltmeter to measure DC volts. Place the red probe on the starter solenoid positive terminal. Place the negative probe on chassis ground. Have someone turn the key switch to "Start" while you measure the voltage at the starter solenoid. The voltage should be approximately 12.6 volts. If the voltage is correct, remove the negative battery cable from the battery. Verify all starter connections are tight and free of corrosion, oil, dirt and debris. Clean the connection with baking soda if the connections are corroded. Reconnect the negative battery terminal and retest. If the engine does not crank, remove the starter and retest.

    5

    Follow the wires from the starter solenoid to the starter relay. Verify that the wires are free of corrosion, abrasion and damage. Clean or repair as required. Place the red probe on relay terminal 85. Place the negative probe on relay terminal 86. Have someone turn the key switch to "Start" while you measure the voltage at the starter relay. The voltage should be approximately 12.6 volts. If the voltage is correct, repalce the starter relay. To repalce the relay, pull the old one out of the socket and insert the new relay. If the voltage is not correct, then there is a problem with the ignition starting circuit. Look for a broken wire or damaged connection from the key switch to the fuse/relay box. Repair the harness as required.

Bad Torque Convertor Symptoms

Bad Torque Convertor Symptoms

A bad torque converter will cause a number of problems for your vehicle. The torque converter is the part that converts the power of your running engine into the force that allows your vehicle to actually move. If the torque converter breaks, seizes up or otherwise malfunctions, you can expect to experience serious problems with your car or truck. Torque converter problems can often be mistaken for other system failures, so it is important to have the vehicle properly diagnosed by a certified mechanic before making repairs.

Transmission Problems

    If the needle bearings inside the torque converter are worn out, you will hear noises when your vehicle's transmission is in gear, but not when the vehicle is put into neutral. If the torque converter stops working, your transmission may overheat and be permanently damaged. Many vehicles have sensors that monitor transmission temperature, which can be an indicator of a torque converter problem.

Slow Acceleration and Loss of Power

    Problems with the clutch on your torque converter can cause the vehicle to lose horsepower or accelerate slowly, even when you are pushing down on the accelerator with more force than usual. Your vehicle may feel sluggish, as if it is having to do more work to maintain the same amount of acceleration and power it usually does.

Overheating

    A problem with the torque converter causes more strain on the engine as it attempts to provide the power the vehicle needs to respond as usual. This can cause the vehicle to overheat. If your vehicle is overheating, especially if it is traveling at a consistently high rate of speed, and you have ruled out problems with the cooling system, you should have the torque converter thoroughly checked out.

Sabtu, 21 Februari 2009

What Causes Engine Oil Leaks?

What Causes Engine Oil Leaks?

An oil leak can be a sign of serious problems with an engine, or it can result from improper maintenance. Depending on the type and size of the leak, engine performance could suffer or the vehicle may not even run. Even a minor oil leak has the potential to become a major problem, and leaks should be located and repaired as soon as possible.

Oil Pan Problems

    One very common cause of an engine oil leak occurs when the oil plug is not installed properly. A loose or cross-threaded oil pan plug can leak in varying amounts ranging from occasional drops to a steady flow out of the oil pan drain. A less-common oil-pan related problem results from a damaged oil pan. Typically, this damage comes from road debris that smashes or punctures the pan.

Seals and Gaskets

    Gaskets become brittle over time and may wear thin or blow out. The result is an oil leak that may or may not be visible beneath the vehicle. For instance, a blown head gasket may force pressurized oil into the cooling system. The primary characteristic of engine coolant that has been contaminated by oil is a frothy, oily residue in the radiator or coolant reservoir.

Pistons and Rings

    Oil can be forced past the rings and pistons, resulting in engine-oil loss. This can be caused by age, excessive engine wear or treatment, poor vehicle maintenance and over-filling the crankcase oil. In this situation, leaked oil may be visible at the exhaust end of the tailpipe, and the exhaust may have a bluish tinge accompanied by a noticeably oily odor.

Cylinder Head

    A cracked or warped cylinder head will allow oil to leak, either out of the engine or into the cooling system. Symptoms of this problem include a loss of cylinder compression or an engine that either runs erratically or not at all. Depending on the location of the damage, oil may leak directly out of the engine in a visible manner.

Valve Cover Problems

    Loose or warped valve covers will allow oil to leak out between the cylinder head and the valve cover. It may be difficult to tell this condition apart from a loose cover and a blown valve cover gasket, and it may exhibit similar symptoms to a blown gasket or cracked cylinder head. The primary indication is a noticeable oil residue on the engine.

Spark Plugs

    A loose spark plug may allow pressurized oil to leak out of the cylinder if the plug is extremely loose or completely missing. Symptoms include a pool of oil around the base of the plug, reduced cylinder compression and a skip in the engine-firing sequence. Additionally, the loose plug may be indicative of stripped threads in the spark plug port, typically indicated by a plug that will not tighten properly or works loose after torque has been applied.

How do I Troubleshoot the Engine on a 1989 Ford Taurus 3.0 V6?

How do I Troubleshoot the Engine on a 1989 Ford Taurus 3.0 V6?

Once a problem develops in a 1989 Ford Taurus engine, you will notice. How you notice depends on where the problem is located in the engine. Of course, symptoms can have a number of different causes. You can troubleshoot the Ford's engine manually, but there are places in the engine that are hard to get to without removing a lot of components just for the purpose of access. This is why the Taurus's Electronic Engine Control system can be helpful. You can create a list of leads just by making the Taurus perform a self-diagnostic test.

Instructions

    1

    Start the Taurus's engine and let it heat up to its usual operational temperature. The air-conditioning system can mess up this process, so make sure the A/C is switched off. After about 10 minutes, turn the Taurus off and pop the hood.

    2

    With the hood open, locate the Self Test Outlet and the Self Test Input. The STO features six ports and is many-sided. The STI is a smaller single port on a wire.

    3

    Insert one end of a jumper wire into STI. Place the other end into the bottom left port on the STO. Return to the driver's seat.

    4

    Turn the Taurus on, but leave the engine off. Count the number of times the check engine light flashes. There will be both long and short flashes to consider. Ford's EEC-IV codes come in two- to three-digit sequences. The first number of a code comes in long flashes, and the second will come in shorter pulse-like flashes. Code 31, for example, will consist of three long flashes and one shorter one. A pause will separate complete trouble codes. Write all the codes down.

    5

    Turn the Taurus off, remove the key, and remove the jumper wire from the STO and STI. You will have to look up the EEC-IV codes on the internet (see Resource section). Once you have located the coding definitions, write the appropriate definitions next to numbers you wrote down in Step 4.

    6

    Return to the Taurus, look into the engine compartment and troubleshoot the areas that correspond with the trouble codes. Cross out numbers and definitions once your investigation eliminates them from consideration.

How to Check for a Compressor's Clutch Engagement

The compressor can be thought of as the heart of a vehicle's air conditioning system. The compressor clutch is what enables a belt-driven compressor to do its job. When the A/C switch is turned on inside the vehicle, electrical current is available to be supplied to the clutch. When the clutch coil is energized, it locks the compressor drive plate to the clutch pulley, causing the compressor shaft to rotate. The rotating shaft moves the compressor pistons, which pressurize and circulate the needed refrigerant. Thus, if the compressor clutch does not engage, the rest of the system will not function. If your A/C is not cooling, one of the first things that needs to be checked (as well as one of the easiest) is whether the compressor clutch is engaging.

Instructions

    1

    Open the vehicle's hood while the engine is off and locate the A/C compressor. Use a flashlight for a better look if it is difficult to see. The compressor is the only belt-driven component with two pipes coming out of it. One of them leads up front to the condenser, which is mounted to the radiator, and the other leads into the passenger compartment, through the firewall at the rear of the engine compartment.

    2

    Study the front of the A/C pulley and notice the drive plate on it. If you look at the other pulleys, they don't have one of these. This plate is what engages the compressor shaft at the center of the pulley. When the A/C is not on or the clutch is not engaged, the pulley turns loosely around the shaft. When the clutch is engaged, the plate locks into place and allows the shaft to turn with the pulley. If the engine is off, you should be able to rotate the plate by hand, unless it is seized. This will allow you to get an idea of how it moves.

    3

    Turn on the vehicle and the air conditioner, then go back and observe the operation of the compressor.

    4

    Listen for the sound of the engagement. You should hear a moderately loud clicking that will coincide with the engagement or disengagement of the clutch as you observe it. Keep in mind that several seconds may pass between cycles before it turns on or off. If you can hear and see it, then the compressor clutch is working properly. If it is not doing anything, then a more in-depth diagnosis will be required by a certified mechanic, who will have both the equipment necessary to properly evacuate the refrigerant according to federal environmental regulations as well as the specific knowledge to perform various electrical and mechanical tests.

Jumat, 20 Februari 2009

Problems With Dirty EGR Valves

Problems With Dirty EGR Valves

The exhaust gas recirculation valve, typically refered to as your car's EGR valve, is one of those parts that most car owners will be completely unaware of unless they experience a problem with it. The EGR valve's main job is to control the formation of nitrogen-based gases and emissions from your engine. A dirty or clogged EGR valve will cause your vehicle to run improperly

Rough Idle

    If your EGR valve is dirty or clogged, your engine will not idle well. Coughing, sputtering and choking while idling are all possible signs of a clogged EGR valve. When the EGR valve is dirty, it may become stuck open and affect your car's ability to idle.

Stalling

    If your car is routinely stalling, your EGR valve may be to blame. Because of the way the vacuum works to control airflow between your intake manifold and your EGR valve, too much vacuum can cause your EGR valve to open completely and stall your motor.

Carbon Buildup

    The "dirt" that clogs your EGR valve and intake manifold is not dirt in the traditional sense. The dirt in this case is carbon buildup from your engine and emissions. When the carbon builds up to a certain point, it hardens and forms a residue. This residue will ultimately clog your intake manifold and EGR valve, stopping them from functioning properly and causing the rough idling and stalling.

Problems With My Camaro Shifter

Problems With My Camaro Shifter

The Chevrolet Camaro has several technical service bulletins, or TSBs, published by the manufacturer on transmission shifter problems. The shifter in both the automatic and manual transmissions have developed problems such as harsh shifting, shutter during normal driving conditions and complete shifter failure because of malfunctions in the computer or linkage.

Transmission Control Module

    A TSB has been published by the manufacturer related to the transmission shifter. The shifter engages the transmission but the car doesn't move. This shifter problem is attributed to an improper programming of the transmission control module. This has created problems with the shifter as well as other transmission components. The Camaro owner must take the car to the dealership to have the control module reprogrammed.

Water in the Transmission

    Water enters the transmission in the Camaro, causing a failure in engagement of forward gears. A TSB is published concerning this shifter problem, which also can cause the shifter to become hard to shift into gears as well as shudder under normal driving conditions. No specific reason is given as to how water is entering the transmission, but the Camaro owner can check the transmission fluid by removing the fluid level check plug on the side of the transmission. Water does not mix with transmission fluid and can be seen in the fluid once some fluid is drained. The transmission will have to be drained and flushed in order to correct this shifter problem.

Difficult to Shift Gears

    The manual transmission can develop shifter problems on low-mileage transmissions of the Camaro, according to a TSB published by the manufacturer. The transmission becomes hard to shift into third, fourth, fifth and sixth gears for no apparent reason. The transmission linkage is considered to be the culprit of this shifter problem. The linkage will have to be readjusted by the dealership because the linkage is not aligned properly. If the Camaro owner continues to operate the automobile under this condition, the car can develop serious transmission problems, including transmission failure.

Signs of Engine Oil Cooler Failure

Signs of Engine Oil Cooler Failure

There are many signs that a car can give that would indicate oil cooler failure. Unfortunately, these symptoms may also indicate other problems so a visual inspection is often needed of the engine to make sure that the oil cooler is the culprit. The most obvious sign of oil cooler failure is physical distention of the radiator and its associated piping.

Decreased Performance

    If the oil cooler is failing in your vehicle, the first thing you'll notice is decreased performance from the engine. This shows up in the form of slower acceleration and a lower possible top speed. The engine will also register a higher temperature on its heat gauge while running. This is because the engine is not being cooled fast enough and is overheating.

Black Smoke

    Smoke is another prominent sign as damage to the cooler may actually cause oil to leak out of the engine and into the combustion chambers. This will cause a thick, black, noxious smoke to come out of the exhausts. This smoke is poisonous, and you should turn your car off once it is safe to do so. Further driving the car may irreparably damage the internal parts of the engine and jam it permanently.

Vibrations

    Vibration is another symptom of oil cooler failure, especially if oil is getting into the combustion chambers. This will cause mismatched explosions in the various cylinders, which will make the engine vibrate out of sync with its proper firing rate. The vibrations can cause damage to other parts of the car if they are allowed to go on for too long. There may or may not be increased smoke associated with this symptom.

Distended Radiator

    A distended radiator is the only sure sign of damage to the oil cooler, along with broken hoses which would prevent the engine from running in the first place. If a radiator has been stressed beyond factory specifications, this can cause the structure to bend and warp. The radiator will look like a football. In the worst case scenario, this will cause the fins to burst out and look like teeth coming out of the face of the radiator.

How to Check the Engine Code P0336

An engine code of P0336 indicates a crankshaft sensor performance problem. It requires a code scanner to extract the codes from the computer. When an erratic signal or loss of signal from a sensor occurs, the computer records the fault in memory in the form of a 5-digit code. It will start with a letter followed by four numbers. The code scanner displays all fault codes stored, which can be cross-referenced with the scanner's accompanying code sheet. This will give a description of the code. A oscilloscope type scanner is necessary to test for irregularities or poor performance on most sensors. It is difficult to check sensors for anything but a major failure with a voltmeter due to their fast duty cycle.

Instructions

    1

    Plug the code scanner into the OBD port under the dash to the left of the steering column. Turn the ignition key to the on position but do not start the vehicle. Record the code or codes displayed by the code scanner. Cross-reference the code with the code sheet to find out exactly what was wrong with the signal. There may be several different problems with one sensor.

    2

    Connect the engine scanner according to the instructions it gives of the specific problem. In this particular case, you are checking the crankshaft sensor since the code denotes a performance problem.

    3

    Check the crank sensors for a clear signal with no dropouts or glitches. The Vantage shows two separate crank sensors -- one a hall-effect (fixed electromagnet that senses metal slots in the crank pulley) that produces a DC signal located behind the crankshaft pulley, the other is a round cylindrical signal generator producing AC voltage located in the side of the block under the exhaust manifold and just above the oil pan on the firewall side.

    4

    Read the instructions on the scanner for the sensor being tested. The first dialogue is a description of operation. The next item is its location, followed by the best test location. In this case, it states that it is easier to test at the ignition control module connector. The next item is the connector, location, color and mission of all wires and voltages on the wire. The last item is the different tests. For this, the oscilloscope is used. A picture is displayed of a good signal for comparison purposes. Start the vehicle and watch the screen for anything irregular. Check all spikes for uniformity: Their peaks and durations should be the same as the illustrated picture. A dialogue is also provided with all the parameters necessary for a clean signal. Any differentiation or irregularities is reason to replace the sensor. If a computer receives an irregular signal, it will lock itself on to the last intelligible signal and will not change until the sensor is replaced.

Kamis, 19 Februari 2009

How to Troubleshoot a Mazda Millennia

The Mazda Millenia is a midsize sedan offered by Mazda from 1995 through 2002. Like many modern cars, the Millenia features an onboard diagnostic system that can facilitate troubleshooting if your Millenia starts to illustrate some bad symptoms. Each component inside your Millenia will output a unique error code, which can be picked up and displayed by the onboard diagnostic code scanning tool. You can obtain a code scanner or have a code scan performed by most auto parts stores, licensed mechanics and car dealerships.

Instructions

    1

    Locate the onboard diagnostic port of your Millenia by feeling around the area below your steering wheel. The port will be located at the top of the driver's side foot well and may or may not have its own spot in the dashboard material, depending on the year of your Millenia.

    2

    Plug the code scanning tool into the onboard diagnostic port, then engage the ignition of your Millenia so that its electronics system is activated. You can either turn the ignition on all the way or to just the accessories position, which is immediately before the engine ignition.

    3

    Allow the code scanner to scan the diagnostic system for any error codes. Take note of any codes that are displayed by the code reader. Decode the error codes by performing a search online, cross-referencing them with a book of possible diagnostic codes, or by bringing the codes to a mechanic or dealership.

Rabu, 18 Februari 2009

Nissan Pulsar Won't Turn Over

Produced between 1978 and 2007 the Nissan Pulsar is one of Nissan's longest running continually produced vehicles. If your Nissan Pulsar won't turn over you must start troubleshooting the electrical system. Usually, the result is a faulty battery but in the event the battery checks out, you must go through the process of troubleshooting the ignition, starter motor and starter solenoid. These components must work in order to crank over the engine.

Instructions

    1

    Check the voltage output of your Pulsar's battery. The battery should put out 12 volts of power when the vehicle is off. To check the battery output. Place the leads of an ohmmeter onto the battery terminals. The red lead goes to positive and the black lead goes to the negative. Place the ohmmeter on 20V DC and check the output reading. If the output is less than 12-volts, charge the battery using an automotive battery charger. If the batter still reads less than 12-volts after charging, replace it with a working battery. If the Pulsar still won't start with a charged or new battery move to the next troubleshooting step.

    2

    Turn on the Pulsar's headlights. This creates a drain on the battery. When you turn on the ignition key, the ignition module sends power sends power to the starter motor and starter solenoid. This creates an additional drain on the battery. The drop in battery voltage should cause the headlights to dim. If the lights fail to dim, the result of your troubleshooting is a faulty ignition module. If the headlights dim, the indication is that the ignition module works and you should move on with troubleshooting.

    3

    Locate the starter motor bolted to the transmission housing. The starter is approximately 8 inches long. The starter solenoid bolts to the transmission housing directly beside the starter. On the bottom of the solenoid, you will find two wires attached to metal lugs. The wire on the left goes to the ignition module and the wire to the right jumps over to the starter motor.

    4

    Touch both metal lugs on the bottom of the starter solenoid at the same time using a screwdriver. This shorts out the solenoid and prevents the engine from turning over when you turn on the ignition. However, it will allow the starter motor to turn on.

    5

    Tell the second person to turn on the Pulsar's ignition key for five seconds. If the starter motor does not turn on or the motor runs intermittent, the starter motor is defective. If the starter motor does turn on and it runs smoothly for five seconds, the starter motor work and the solenoid is defective.

What Are the Signs of a Faulty Fuel Filter on a Vauxhall Vectra?

Since the mid 1990's, the Vauxhall Vectra has garnered recognition as a mechanically sound vehicle. However, even a reliable vehicle requires maintenance and the occasional repair, such as the replacement of a faulty fuel filter. Becoming familiar with the signs of a faulty fuel filter on a Vauxhall Vectra can prevent one from being inconveniently stranded due to complete failure. The symptoms of a failing fuel filter are fairly easy to discern.

Sputtering

    Sputtering is among the most common signs of a faulty fuel filter on a Vauxhall Vectra. When the fuel filter is not letting fuel pass through freely, then the engine is not getting the fuel it needs to run smoothly. The result of that is sputtering when the accelerator is pressed. Typically, this is caused by the fuel filter being partially clogged. Clogs are often the result of particulate matter in fuel or by running out of fuel, which allows the fuel pump to suck sediment from the bottom of the fuel tank into the fuel system.

Stalling

    Stalling in a Vauxhall Vectra is another symptom that can indicate a failing fuel filter. A problem with a fuel filter can prevent the engine from getting the fuel it needs to stay running while idling and can cause a failure in meeting fuel demand for a quick acceleration, causing the vehicle to stall.

Surging

    When the fuel filter in a Vauxhall Vectra is partially clogged or has another problem that interferes with the flow of fuel, surging can result. This unexpected acceleration happens because suddenly the standard flow of fuel is restored, providing the engine with what it was straining for and allowing it to surge.

Less Power

    A problem with a fuel filter in a Vauxhall Vectra can result in a less power overall, particularly noticeable in driving situations in which quick response is desired, such as passing. This is simply because the fuel filter is limiting the amount of fuel available to the engine and, thus, interfering with its ability to create the amount of power it is capable of.

Failure to Start

    When the fuel filter ceases to function due to a complete obstruction or other problem, it can cause the vehicle to fail to start. Without receiving the fuel it needs for the combustion process, the engine cannot start and run.

2003 Chevrolet Impala Electrical Problems

2003 Chevrolet Impala Electrical Problems

The 2003 Chevrolet Impala was one of GM's most popular cars in that year. With an average highway fuel economy of between 29 and 32 mpg, according to Cars.com, this make of car is extremely efficient and fairly reliable. Though no serious problems were ever documented by GM and Chevrolet, there are numerous electrical problems that consumers have had with the car. These electrical problems range from as minor as lights turning on without notice to the engine shutting down while driving.

Engine Doesn't Start

    One of the more common problems in the 2003 Chevrolet Impala, according to Carcomplaints.com, this usually happens around the 80,000-mile mark of the car and costs about $500 to repair. What often happens is that the key is unable to turn the ignition and therefore the engine is unable to start. What occurs inside the ignition is that parts have moved around or shifted and the key is unable to reach each part of the inside of the car. When this happens the best thing to do is to have it repaired by the dealer or a mechanic. However, many have found it possible to start the car by putting some kind of lubricant on the key and moving it in and out of the ignition hole to coat the inside. This sometimes allows the key to hit the parts it needs to be able to turn the ignition and start the engine. In fact, Chevrolet even had a small recall early in the model's existence to fix this problem.

Security Light Comes On

    Occurring most often around 100,000 miles, the security light often can come on when it is extremely hot outside. When this happens, the interior and exterior lights flash and other electrical features, like the air conditioning, do not work, according to Carcomplaints.com. If it occurs when the car is off, the engine will not start and you will need to either get the car jumped or get it towed to a mechanic. This problem also can occur after driving long distances. It can be fixed by taking it to the dealer or a mechanic to get the problem diagnosed and healed.

Engine Shuts Down While Driving

    Though not as common as other electrical problems, this 2003 Chevrolet Impala problem is one of the major and most dangerous problems the car has. It happens at about 95,000 miles and can cost over $1,500 to repair. When the problem occurs, the engine shuts down completely, with no response from the transmission, acceleration or brake. It is extremely dangerous and can cause accidents and other car problems. Many mechanics have been unable to find a cure for this problem, so the best antidote is to contact the Chevrolet dealer and have them examine the car and perhaps even replace the model.

Reasons for a Dead Car Battery

Reasons for a Dead Car Battery

A dead car battery can leave an auto owner surprised and stranded after he discovers his car will not start. Often a car battery can be recharged by connecting jumper cables to a second vehicle, but a dead car battery still is a cause of frustration to someone who needs to be somewhere at a certain time. There are numerous reasons a car battery may die, and some causes are avoidable.

Leaving Lights On

    When a vehicle is running, a car battery is recharged by the charging system, which includes the alternator and voltage regulator. As long as a vehicle is running, the battery is usually recharged faster than it is drained by auto accessories. When headlights, interior lights or trunk lights are accidentally left on for a long period of time when the car is not running, these lights are being powered by the battery. Eventually, the battery will die and the car will not start. Leaving the radio or air conditioner on when the car is not running can have the same draining effect.

Problems with Charging System

    A dead battery can be caused by a problem in the charging system. Problems with the alternator can lead to the battery not being charged properly. Loose or corroded connections between the battery and the attached cable can also lead to a dead battery.

Not Starting Car Enough

    A car that is not started enough or is not used frequently in cold weather can cause a dead battery. A car that is in storage may have a dead battery when the owner tries to start it. A car battery may also freeze in extremely low temperatures if not used regularly, causing the battery to die.

Old Battery

    An old or worn out battery does not hold a charge efficiently. Thus, the age of a car battery can be the cause of a dead battery.

How to Troubleshoot a 1994 Infiniti J30

How to Troubleshoot a 1994 Infiniti J30

The Infinity J30 was introduced in 1992 and remained in production until 1997. The Infinity brand is the high-end line of cars manufactured by Nissan Motor Company of Japan. The J30 is a rear wheel drive four-door sedan that features a 3.0-liter, 6-cylinder engine. If your Infinity J30 is not performing as you expect, there are a few things you can do to troubleshoot it at home before taking it into a mechanic.

Instructions

    1

    Insert the key for your 1994 Infinity J30 into the ignition and turn the key to start the engine. Part of troubleshooting the Infinity J30 is listening for any unusual sounds when you turn the key. If you hear a clicking noise coming from the bottom of the engine compartment, it may be an indication that the starter motor is malfunctioning and needs to be replaced.

    2

    Turn the key, and if the engine turns over slowly or barely at all, stop trying to start the engine, pull the engine hood release and open the hood to the engine compartment. Inspect where the battery cables are connected to the battery. If there is corrosion on the connection, use a wire brush to remove the corrosion. If the corrosion is very bad, mix a cup of water and a tablespoon of baking soda. Pour a little bit of the mixture onto the connection to loosen the corrosion and use the wire brush to clean it off.

    3

    Take the Infinity J30 for a test drive. Press the accelerator and see how it responds. If you notice a hesitation when you use the accelerator, it may be an indication that the fuel filter is plugged. Remove and replace the fuel filter and take the J30 for another test drive. If the same problem exists, the fuel injectors may be clogged and need servicing. There are gas additives that may resolve the problem. If the problem persists, the injectors will need to be cleaned by a mechanic.

    4

    Drive the Infinity J30 to an empty parking lot. Accelerate, then press the brakes firmly. If you notice a pulsing feeling in the brake pedal or in the motion of the car, it may be an indication the brake rotors are not wearing evenly. This should be looked at as soon as possible, as it will affect the brakes' ability to stop the car.

Selasa, 17 Februari 2009

What Does a Brake Modulator Do?

What Does a Brake Modulator Do?

An ABS brake system modulator does exactly what it sounds like it does: it modulates pressure between individual wheels to keep them right on the verge of lockup. If the computer is your ABS's brain, and the wheel-speed sensors its eyes, then the modulator valve body is its muscle.

Brake Lockup

    When you push on the brake pedal, you're pushing on a rod connected to the back of a piston. This piston sits inside of your car's master cylinder, where it pushes fluid through the lines and to the individual wheels' brake cylinders. When a tire loses traction for whatever reason, pressure supplied by the system causes the brake pads to lock against the rotor or drum, bringing the wheel to a sudden halt called "lockup." Once that happens, the tire slides and is essentially useless.

How ABS Works

    Without ABS, you'd have to lift your foot off the brake pedal in order to get the wheels spinning and useful again. An ABS system works by doing this for you not only with the system as a whole, but with each wheel individually. But instead of "lifting off the pedal," an ABS modulator reduces pressure to the locked-up wheel by sending some of it back to the brake fluid reservoir through a bypass line. When the computer detects lockup through the wheel-speed sensors, it momentarily opens the bypass valve and, thus, reduces the fluid pressure being applied to that wheel.

Open Systems

    Open systems are the simplest type, but they have one serious drawback. An open system works just as described above, sending excess fluid back to the chamber under lockup. The problem with this arrangement is that every time the modulator releases pressure, the brake pedal drops a little bit. So, under sustained braking events, either the brake pedal will drop to the floor, or the driver will have to lift to restore pressure. Some open systems, though, use a pump to re-supply the master cylinder with fluid to keep the pedal from dropping.

Closed Systems

    With a closed system, vented pressure goes either back to the reservoir or to a spring-loaded cylinder called an accumulator. The accumulator holds pressurized fluid on standby for quick release back into the system after the initial pressure drop. If there isn't enough pressurized fluid stored in the accumulator, a brake fluid pump sends pressurized fluid to it to refill it. A closed system operates in a constant vent-pressurize cycle to keep fluid pressure at the highest it can be without inducing lockup. Because of this, closed systems are typically a bit better at maintaining the type of "threshold braking" needed to extract maximum performance from the brakes.

My Jaguar XJ6 Power Seats Won't Work

My Jaguar XJ6 Power Seats Won't Work

The Jaguar XJ6 sedan offers its occupants a wide range of features and accessories, including power seats. As in all cars, though, the Jaguar's power seats are only a convenience until they stop working. Diagnosing and repairing completely inoperative XJ6 seats requires only a few common tools and can bring the luxury back to a luxury vehicle.

Instructions

    1

    Open the vehicle's trunk. Lift the right hand portion of the trunk floor to access the vehicle's battery. Use the 10mm wrench to loosen the negative battery terminal, and disconnect the terminal from the battery. Lay the negative battery cable and terminal aside so that it cannot touch the negative post of the battery. Leave the battery disconnected for 15 minutes, and then re-connect the battery. Make sure the battery terminal is firmly tightened to the battery post, and re-install the trunk floor panel. Close the trunk, and check to see if the seat is still inoperative. The process of disconnecting the vehicle battery and re-connecting it is called a hard reset, and is often the only thing needed to fix XJ6 computer malfunctions. If your seat still does not function, proceed to the next step.

    2

    Locate the heelboard fuse boxes at the base of the back seat lower cushion. These fuse boxes are behind the carpeted panels below the front edge of the rear seat. Use the flat-bladed screwdriver to turn the round fastener in the middle of the carpeted panel. Turn the fastener 1/4 turn in either direction to release the panel, and pull the entire carpeted panel forward to reveal the fuse box. Set the panel aside, and remove the panel for the other fuse box the same way.

    3

    Connect the negative lead of your Volt-Ohm meter to any available ground point on the vehicle. The vehicle's body is connected to battery ground, so any clean connection to the body will work. Turn the vehicle's ignition on, but do not start the engine. Check for battery voltage at fuses F3, F4, F9, and F12 in the right hand heelboard fuse box, and F6 in the left hand heelboard fuse box. Use the positive lead of your meter to test for power at both exposed terminal points on each fuse. If any fuse lacks power on either of its terminals, pull the fuse out of the fuse box and look at the conductor inside the fuse's inspection window to see if it is intact. If any fuse's internal conductor is burned, replace the fuse with a fuse of the same current rating. If you replace a fuse in this step, check if the power seat functions properly after the fuse replacement.

    4

    If the seat still does not function, use the T40 Torx socket and socket wrench to remove the 4 bolts holding the driver's seat to the floor. The bolts are located at the ends of the two black metal seat rails underneath the seat. Tilt the entire seat assembly back to gain access to the underside of the seat. Locate the seat control module underneath the driver's seat. Identify the two blue connectors on the seat control module. One connector has 22 wire locations, and the other has 12 wire locations. On the connector with 22 locations, find the white and pink wire in the 11th wire location.

    5

    With the ignition on, use your meter to test for power at the wire. If there is no power at the wire, test for continuity between the white and pink wire and fuse F12 in the right hand heelboard fuse box. If there is no continuity, there is a break in the wire between the fuse box and the seat that must be repaired. Turn the ignition off. Check for power on the 12-location connector at wires 4, 6, 7, and 12. Wire 4 is colored brown and green, wire 6 is brown and light green, wire 7 is brown and orange, and wire 12 is brown and gray.

    6

    If any of these wires does not have power, check for broken conductors between the control module and fuse box. Use your meter to check for continuity from wires 4 and 6 to right-hand heelboard fuses F3 and F4, respectively. Use the meter to check for continuity from wires 7 and 12 to left-hand heelboard fuses F6 and F9, respectively. If any of these wires does not have continuity, there is a break in the wire that must be repaired.

    7

    If all fuses are intact and power is present at all the wires tested in the previous step, replace the seat control module and use the T40 Torx bolts to re-install the seat. Control module failure is common, but testing the wiring before replacing the module can avoid replacing a module unnecessarily.