TECH TIP SEARCH RESULTS
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Acura Legend Transmission Problem
The leak from the sunroof on the Acura Legend could cause a TCM (transmission computer module) to burn out. Plugged drain tubes cause water to accumulate and leak down to the floor were the TCM is located. The repair is to clean up any debris, and check the plastic tubes for clogging: they're located at the front mud flap and trunk quarter panels
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Audi 5000 Transmission Problem
The Audi 5000 might have a transmission problem in low and reverse. The problem is that the transmission accumulator piston seal is torn, causing drag or a shifting problem. The fix is to remove the transmission pan, filter, valve body and accumulator, and once the accumulator piston is out, check for rough edges then clean up and install a new seal. Don’t forget to install the recommended amount of transmission fluid.
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Audi and VW Computer Problems
Loose ground wires could cause the computers on Audis and VWs to instantly burn themselves out. When doing any engine work--such as valve covers, water pumps, engine mounts, head gaskets, etc.--always check that ground straps are properly insulated and tightened. The ground straps, mounting screws and threads must all be cleaned and tightened properly or a voltage drop will occur. If there is an excessive voltage drop, the computer will be damaged
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Audi Steering Problems
The 1998 and 1999 Audi A4, A6, and A8 models have a problem with reduced steering control. The problem has been linked to inadequate sealing of the ball ends that are installed on the rack-and-pinion tie rod ends. There has been a recall involving these vehicles whereby Audi will replace the tie rods. For further information contact Audi at (800) 822-2834.
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Bad Engine Ground
The poor engine ground connection could cause corrosion of the radiator or other metal coolant components. This process is called electrolysis. Electrolysis usually takes place when an engine ground becomes loose or corroded. You can check for this condition by using a Digital Volt Meter. To do so, attach the black end of the meter lead to a good ground (negative side of the battery), and then connect the red lead so it make contact with the coolant in the radiator. Next, crank the motor over, making sure that the test lead does not touch any part of the radiator or the results will be invalid. CAUTION!!! Care must be taken when dealing with hot engine coolant. Follow all safety precautions and NEVER OPEN THE RADIATOR WHEN HOT!!! If the meter reads more that 0.3 (300 millvolts) you have a problem
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BMW 525i Dead Battery
Incorrect routing of the alternator belt causes the belt to slip and the battery to go dead. The belt must be checked for correct routing and proper tension. The smooth side of the belt goes against the flat pulley and the grooved side runs against the notched pulley. Charge the battery with the battery cables disconnected from the vehicle, and then test the battery and the charging system. Follow all safety and manufacturer recommendations.
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Brakes That Growl
Did you know a growling or grinding noise coming from your brakes could be an indication that you may have brake trouble. Most disc brakes installed on vehicles have a wear sensor installed on them.When brake pads get low the sensor will hit the rotor, this warning system emits a growling or scrapping noise to remind you to have the brakes checked or replaced. In order to prevent any damage to the rotor surface or caliper you should have your brakes looked at by a mechanic immediately. Don't forget it's the most important system on your vehicle.
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Chevy Lumina air bag problems
Their bag problems have led to a recall for the 2000 Chevy Lumina and the Pontiac Grand Prix built from September through October 1999. If you have a vehicle built during this period, contact Chevy at (800) 222-1020 or Pontiac at (800) 762-2737 immediately. The build date can usually be found on the driver’s-side door or pillar
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Chevy MIL (Check Engine Light) On
Topping off your fuel tank could cause the MIL light to come on. Yes, overfilling the gas tank will cause the check engine light to come on. This computer system is very sensitive to all fuel system functions on new OBD II equipped vehicles. The light will usually come on after fueling during short trips more so than extended driving trips. The fix for this problem is not topping off (overfilling) the gas tank.
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Chevy, GMC and Olds Trucks with Transmission Problems
1995 to 1998 trucks might experience transmission problems caused by a faulty dipstick tube seal. This seal is located between the transmission case and tube. After the seal has been replaced, the transmission should be flush and refilled. Professional equipment is needed to properly flush all of the contained transmission fluid.
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Chrysler Cirrus, Dodge Stratus and Plymouth Breeze Brake Problem
The Cirrus, Stratus and Breeze built from June 1997 through May 1999 might experience brake failure. The right rear brake line comes in contact with the exhaust system clamp. Symptoms include brake fluid loss and poor braking performance. The fix is to install a new brake line and bleed system, and to reposition the exhaust clamp. For recall repair info, contact Chrysler at (800) 992-1997
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Chrysler LHS & Dodge Intrepid Transmission Problems
Cars equipped with the 3.5-liter engine could have transmission problems caused by a faulty thermostat. The thermostat controls engine temperature, which is monitored by the vehicle's computer system. The signal from the cooling system can give the incorrect signal, causing transmission commands to lock up, engaging or disengaging the transmission. The symptom will be a bucking or surging problem. The coolant should also be checked for proper level and the thermostat operation should be checked as well. Use caution when working around hot engine coolant and parts.
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Clean Carbon Build-up from Engine
The best way to clean carbon build-up out of your engine is NOT to take the car out and run it as hard as you can. This only results in meetings with local law enforcement personnel, and doesn't do much for cleaning out carbon.
If you really want to clean the carbon out of your engine follow these simple steps. Fill an empty soda bottle with water. Remove your air cleaner. Start your engine. While using one hand to control the throttle, trickle the water into the carb or throttle body with the other while holding your thumb over the bottle opening. Keep the engine rpm's up so that the engine doesn't die. Make sure that you don't pour the water in too fast! Water doesn't compress and if you pour too much water in, severe engine damage can result! White smoke from the exhaust is normal. If you have a port fuel injected car, you obviously won't be able to use this method, but I have had success with connecting a vacuum hose to a port at the base of the throttle body and sticking the other end of the hose into the bottle of water. The vacuum of the engine will suck the water in, creating the same effect. This will clean out even the most stubborn carbon, by 'steam cleaning' your cylinders.
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Dodge Caravan and Plymouth Voyager Misfire
Both the Caravan and the Voyager equipped with the 2.5-liter engine could experience a misfire due to an air conditioning relay? The problem with the misfire is usually experienced when the air conditioning is turned on. Check for codes in the computer system and check the relay for proper operation. The fix for the problem is to install a new relay, along with an additional ground wire to the relay.
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Dodge Dakota Hard Start
The 3.9-liter Dodge Dakota could experience hard starts due to a fuel injector problem. The problem is that the fuel injectors leak, causing extra fuel to be dumped into the cylinder. This contaminates the oil and empties the fuel rail. When the ignition key is turned on, the lack of fuel in the rail causes a hard start or extended cranking time. The fix for this problem is to replace the fuel injectors and seals and to change the oil. Observe caution when working with the fuel system, and follow all safety procedures
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Dodge Shadow Cruse Control Problem
The Dodge Shadow could have a problem with the cruise control system, due to a brake switch problem. The brake switch is a major input for the cruise control system; its signal is used to communicate with the computer to turn off the cruise control. The problem is with excessive resistance at the brake switch, causing poor or no cruise control input. Check all connections for excessive voltage drops. Consult an ASE technician for proper procedures.
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Ford F-350 Truck Wiper Problem
The intermittent wiper might not work because of a faulty wiper motor. The problem that Ford has been having is that wiper motor circuit board has been failing, leading to occasional or total non-operation. Check with Ford if your truck has this problem.
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GM 2.4-liter Engine Problems
The 2.4-liter engine in the Chevrolet Malibu, Chevrolet Cavalier, Oldsmobile Alero, Pontiac Grand Am and Pontiac Sunfire can idle roughly or misfire? This can set off a P0300 code and illuminate a MIL (check engine light). The cause is a missing spark plug boot spring that is used in the direct ignition coil pack. Replace the missing spring and boot assembly to repair this problem. Caution: When working on ignition systems, follow all safety and manufacturer-recommended procedures.
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GM Vehicle Transmission Problem
Your GM vehicle might experience transmission problems due to a faulty switch/sensor. The transmission may not shift properly due to fluid that leaks past the electrical connector.This switch/sensor connects the transmission to the TCM (transmission computer). The transmission fluid passes through the switch/sensor and up through the wires, preventing the computer and the transmission from communicating. The fix for this problem is to replace the switch/sensor and install a new wire plug connector. The wire plug connecter has to be spliced into the existing harness and must be soldered and heat shrunk. Take all precautions when working with the electrical and computer systems.
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Hard Starting Jeeps Cherokees
Extended cranking or hard starting Jeeps could mean you have a fuel problem. Jeep Cherokee has had a starting problem due to a trouble with the rubber hose that is connected to the fuel pump. This rubber hose can become porous allowing fuel pressure to drop. To check for this problem turn the key to the run position (do not crank engine) and listen for the fuel pump. The fuel pump should run for a couple of seconds. After the pump stops turn the key to the off position and then back to run. This action allows the pump to deliver fuel and fill the rail back up. Care must be taken when installing a fuel pump, first make sure that the hose installed is fuel injection rated and do not over tighten the clamps.
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How to Change BMW Battery?
Once you are sure you need to replace your battery you can either pay someone else to do it for you, or do it yourself.
If you decide to save money on labor, first thing you need to do is get the right battery. It's easy, just ask the parts seller to look up the correct application. Make sure you are getting the same amp battery as listed for your car.
Exchange procedure is quite simple and takes about ten minutes. You will need a crescent wrench and a screwdriver.
Begin with loosening the casble clamps attached to the battery terminals. Remove the negative battery cable FIRST, and reconnect it LAST. Then unscrew the hold-down brace which keeps battery in place. Take out old battery and place a new one instead, reversing the whole procedure.
That's it! Your done!
Before closing the hood of your new battery, make sure all cables and terminal ends are clean and not cracked. This will assure positive connection.
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Improve Fuel Economy - Four Easy Ways
1. Keep your car in good shape. Fixing a car that is noticibly out of tune can improve your gas mileage by 4%. For example, exchanging a bad oxygen sensor makes your gas mileage as much as 40% better!
2. Plan and combine your trips. Several short trips started from cold engine will use more fuel than one combined trip on a warmed-up engine.
3. Drive Sensibly. Agresive driving wastes gas. You can save money on gas by avoiding speeding, rapid accelaration ans braking.
4. Purchase a K&N Air filter. They are a cheap and proven method to increase gas mileage.
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Jeep Blown Fuse
Fuse No. 16 on the Jeep Cherokee has been known to blow because of a melted wiring harness. The oxygen sensor wiring harness is located too close to the exhaust manifold on the 4.0-liter engine, causing the harness to melt. The proper repair is to solder the wires, strap the wiring away from the exhaust manifold, replace fuse No. 16 and test the oxygen sensor for proper operation. If you are unsure of the procedure and repair, consult with an ASE-certified technician.
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Nissan Sentra MIL Problem
The MIL (check engine light) might illuminate because of a computer problem. The 1997 and 1998 Sentras can report a PO300 (random misfire code) for a misfire that does not exist. This false MIL stored in the PCM is caused by a design defect in the PCM. Diagnostic procedures must be followed for the misfire code. This will include checking all mechanical and related systems. If no problems are found, the PCM should be replaced.
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Oldsmobile 3.8L Stall Out or No Start
The 3.8L engine may have a no-start or stalling problem due to dirt, ice or snow. This engine is equipped with a Hall Effect crank sensor located on the lower part of the engine next to the harmonic balancer. When road dirt, ice or snow get stuck they can either break the sensor or cause an interruption of the generated signal. When the sensor doesn't send the correct signal to the computer it causes a stalling or no start problem.
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Plowed In
Your vehicle may not start when it has been plowed in. Snowplows push snow off the roadway as close as possible to the curbs, sometimes blocking your vehicle in. The snow is packed all around your vehicle and possibly into the exhaust pipe (tailpipe). The snow then freezes and doesn't allow release of exhaust to leave the system. Your engine works on the principle of taking in fresh air from the air cleaner, mixing with fuel and then releasing the byproducts of combustion through the exhaust. When snow gets packed inside the exhaust system your engine will not run but it will crank. This can also happen when parking. Be cautious when backing up into a pile of snow. Always remember to check your exhaust pipe for blockage.
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Save Money by Inspecting Your Brakes
Save money on brake repairs by inspecting your car every 6 months! Here is what you should look for:
1. Take a look at your brake rotors (disks). If any visible defect or discoloration - exchange them immidiately.
2. Inspect your brake pads for any uneven wear breakage or cracking.
3. Visually inspect your brake drums for the same defects as listed above.
4. Brake shoes - look for signs of uneven wearing or rivets to the friction surface
5. In addition to all above steps - inspect your calipers, wheel cylinders, hoses and fittings for any fluid leakage.
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SCAN Tool Readings
It is easy to make snap, incorrect, judgments about what is wrong with a car based upon the SCAN tool reading. Take the time to look at all the parameters. Just because there is a code for an EGR valve not opening, does not mean the EGR is at fault. I showed one of my techs how a bad thermostat and/or CTS would not allow the EGR control to function. Replacing the CTS corrected the pinging, and erased the EGR code. Take the time to look at ALL the parameters. And don't forget to run the gearshift lever through all its positions. If the PRNDL is not reading correctly, the PCM doesn't make the correcting decisions for timing, EGR control, etc.
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Transmission Problems in Chrysler LHS
Transmission problems may be caused by a faulty thermostat in the 3.5L engine. Engine temperature is controlled by the thermostat, which is in turn monitored by the vehicle’s computer system. An incorrect signal can be sent by the cooling system, causing transmission commands to lock up. This can result in a bucking or surging problem. The thermostat should be checked for proper operation and the coolant should be kept at proper level. Always use caution when working around a hot engine.
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Vacuum Hose Problems
Inspect those vacuum hoses. They either become misrouted, or they deteriorate and collapse. We had a Dodge Colt Vist (Mitsubishi) that would go lean at highway speeds. Went through everything, until we checked vacuum line routing. The lines going to the High Altitude Compensator (opened a vacuum port in the main jet that reduced the fuel by breaking the siphon) were reversed, so the engine ran out of fuel. Have seen lots of misrouted lines causing similar problems, so get out the charts. Check it out yourself. Check the condition for all the vacuum lines to prevent pinhole leaks from driving you crazy.
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Vehicle Problems on Bridges & Overpasses
During cold weather overpasses and bridges freeze before the regular roadway freezes. Overpasses and bridges freeze first because they are structures that are above ground level and cold air completely surrounds them. You should slow down and avoid all sudden changes in direction as well as speed. Care must also be taken when applying your brakes.
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Vehicle With a 'Questionable' Maintenance Record
If you purchase a used car with a 'questionable' maintenance record, it's a good idea to add automatic transmission fluid to the crankcase and run the engine for a few minutes before changing the oil. This will clean out a good portion of the sludge and build-up from the inside of the engine.
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Volvo 240 No-start
The Volvo 240 might not start because of a clogged flame trap. The flame trap is the positive crankcase ventilation system that allows blow-by gases from the engine to be introduced into the intake system. This system vents the gas to prevent engine seal leaks and lowers emissions. Difficult starting can be accompanied by a MIL (check engine light) with an oxygen sensor code. The code is set to the clogged flame arrester problem. Check the flame trap screen for clogging and replace as necessary.
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Why Engine Thrust Bearings Fail
Often, soon after an engine rebuild, premature engine thrust bearing failure occurs. We will discuss some of the major causes of these types of failures.
One of the most common causes of thrust bearing failures is the transmission torque convertor. When the overrunning clutch in a torque convertor becomes either seized or will not lock up in one direction, the stator does not provide it's normal function of directing the transmission fluid to create the proper torque multiplication required to drive the vehicle. When this happens, a large amount of the energy created is exhausted through the center of the torque convertor, creating excessive forward pressure. It is this pressure which causes the engine thrust bearing damage. When installing a new engine, it is wise to check the convertor your self, or have a qualified transmission rebuilder inspect it for over running clutch problems.
Improper installation of the torque convertor in the transmission front pump can also lead to bearing failure, as well as transmission failure.
Vehicles with standard transmissions may also experience this type of engine failure due to high clutch pressures, usually related to performance clutches with high spring pressures being installed. Riding the clutch can also cause thrust bearing failure on new engines. You must also ensure the clutch has adequate free play.
Symptoms of damage caused by excessive external pressure on the crankshaft vary on engines due to their design differences.
Small block Chev engines usually suffer catastrophic damage from excessive external pressures. In most cases the thrust bearing show signs of heavy rubbing on the thrust bearing. The most severe damage it on the other mains bearings, with the highest wear being on the center bearing, usually concentrated on the lower half of the bearing. The intermediate main bearings will have about half the wear of the center bearing, with the front and rear bearing showing little sign of problem.
Big block Chev engines, due to the rigidity of their crankshaft, will usually only destroy the thrust face of the thrust bearing, causing little damage to the other mains.
Engines with a center thrust bearing usually, as well as rubbing the thrust surface, will show signs of wear on the opposite sides of the crankshaft on the two intermediate bearings.
I have seen cases of thust bearing failure on small block Ford engines that do not seem have an apparant cause. Upon checking the inner part of the bearing that seats in the block, signs of scraping on the bearing were noticed. This is the result of the installer trying to install the bearing in the rear location instead of the center, where the thrust bearing is located in this type of engine.
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Why Oil Pumps Fail?
Tight tolerances make for a precarious existence for this critical component.
Oil pumps don't always need to be replaced when oil pressure drops, but when one does need to be replaced, it is important to know the ins and outs of oil pump failure.
By far the most common reason for an oil pump to fail is from dirt or debris in the lubrication system.
According to some data, prime culprits include wire bristles from cleaning brushes, valve seal material, and other assorted dirt. When one considers that oil pump clearances are in the order of .003", it is not hard to understand why foreign material can cause oil pump failure.
Pieces of nylon cam drive gears have also ended up in oil pumps. Don't expect the screen to filter out these objects as most have a bypass hole or slots designed to allow oil to flow when the oil's viscosity is too high to flow effectively through the screen. A cold start and a piece of debris can quickly lead to oil pump lock-up.
So, whenever an oil pump is being replaced, jobbers should advise their customers that oil systems should be flushed out thoroughly. Debris can also end up in the pressure relief valve, possibly causing pressure to bleed off leading to a low oil pressure situation, perhaps ending up in engine damage.
In addition, manufacturers have reported that there appears to be an increase in post rebuild engine failures as a result of the oiling system failing to prime itself. Reports from warranty claims have revealed completely dry oil pumps in some cases. To avoid this, jobbers should advise all customer to immerse pumps in oil and hand prime the oil pump before installation. Furthermore, it is not advisable to use petroleum jelly, lithium grease lubricants as a prelube in the oil pump, or liberally in the engine at all as they do not pump and can fill the pumping channels, curtailing is ability to move oil.
For engines that are already assembled, but have been shipped or left sitting in storage, it is particularly advisable to pressurize the entire oiling system prior to start up using an electric drill as the oil pump may not be able to pressurize the system quickly enough to prevent damage. This procedure should be performed on any engine that has been assembled, before start up, to prevent dry start.
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