Mess of problems
05-15-2009, 02:51 PM
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Mess of problems
Ok so im new here. i have a 1991 audi 200 quattro 20 valve turbo. I love my car but recently everything is falling apart. When i would start it, it would miss for about 4 or five minutes due to plugs being soaked in oil from a leaky valve cover gasket. so i cleaned it up and replaced the gasket. It still misses when cold. And for a while i was leaking a small amount of coolant just enough to throw the light on every 3 weeks. Now its leaking coolant enough to put the light on in about 2 days. The cylinder that currently misses when the engine is cold is one that wasnt effected with oil from the leaky valve cover gasket. and im hoping my coolant isnt leaking into the head through the head gasket. does anyone have any ideas what might be going on causing these things to happen and ways to test to make sure thats whats wrong with my car. everyone is telling me to get rid of it but i really like it and want to keep it running.
05-15-2009, 06:20 PM
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Hard starting and rough idling when cold CAN result from tired plug wires. Try spritzing the wires with some water in the dark and see if you get any spark arcing. GOOD wires for these cars are expensive.
Do you see any coolant drips anywhere? When the car is hot, and you shut it down, check for really fine sprays of coolant. I just developed a pinhole leak in the plastic overflow reservoir. I've had radiators that seep small amounts of coolant under the pressure that builds up after shutting down that just leave wet spots on the coils. Test the tightness of hose clamps that are in the out-of-way places like the line off the bottom of the reservoir and the small hose that runs between the coolant manifold pipe along the driver side of the engine and the pipe that goes around the front of the engine (behind the timing belt cover) to provide coolant for the turbo. Check behind the head for the line to the heater valve. Look under the rain diverter for loose connections to the heater core.
Do you see any coolant drips anywhere? When the car is hot, and you shut it down, check for really fine sprays of coolant. I just developed a pinhole leak in the plastic overflow reservoir. I've had radiators that seep small amounts of coolant under the pressure that builds up after shutting down that just leave wet spots on the coils. Test the tightness of hose clamps that are in the out-of-way places like the line off the bottom of the reservoir and the small hose that runs between the coolant manifold pipe along the driver side of the engine and the pipe that goes around the front of the engine (behind the timing belt cover) to provide coolant for the turbo. Check behind the head for the line to the heater valve. Look under the rain diverter for loose connections to the heater core.
05-15-2009, 07:02 PM
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Hard starting and rough idling when cold CAN result from tired plug wires. Try spritzing the wires with some water in the dark and see if you get any spark arcing. GOOD wires for these cars are expensive.
Do you see any coolant drips anywhere? When the car is hot, and you shut it down, check for really fine sprays of coolant. I just developed a pinhole leak in the plastic overflow reservoir. I've had radiators that seep small amounts of coolant under the pressure that builds up after shutting down that just leave wet spots on the coils. Test the tightness of hose clamps that are in the out-of-way places like the line off the bottom of the reservoir and the small hose that runs between the coolant manifold pipe along the driver side of the engine and the pipe that goes around the front of the engine (behind the timing belt cover) to provide coolant for the turbo. Check behind the head for the line to the heater valve. Look under the rain diverter for loose connections to the heater core.
Do you see any coolant drips anywhere? When the car is hot, and you shut it down, check for really fine sprays of coolant. I just developed a pinhole leak in the plastic overflow reservoir. I've had radiators that seep small amounts of coolant under the pressure that builds up after shutting down that just leave wet spots on the coils. Test the tightness of hose clamps that are in the out-of-way places like the line off the bottom of the reservoir and the small hose that runs between the coolant manifold pipe along the driver side of the engine and the pipe that goes around the front of the engine (behind the timing belt cover) to provide coolant for the turbo. Check behind the head for the line to the heater valve. Look under the rain diverter for loose connections to the heater core.
05-20-2009, 12:52 PM
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First off im very wordy, so please excuse the length of the post...=) I second when everyone else has said, and have a few additions:
there is usually a pretty good seal between the plugs the the cylinger head, so unless the oil was somehow getting inside the plug wires, i dont think the valve cover gasket would be the cause for misfiring.
the easiest way to determine a dead or weak cylinder is to eliminate each contributor (fuel and spark) one at a time. if memory serves, you have the 3b engine with Electronic Fuel Injection (EFI).
Check to be sure your cold start injector is plugged in and functioning. if you suspect its not firing, remove it from the engine but leave it plugged in and connected to its fuel line. disable the engine from running by unplugging the wire from your coil to distributor and place the injector in a cup to catch the fuel. have a friend crank the engine over (you can remove the spark plugs to reduce strain on the starter if you want, but its not critical) and watch to see if the injector fires. if it does, and has a nice even spray pattern, its good. reinstall the injector and your plug wire and start the engine. unplug the other fuel injectors one at a time. if you hear a difference in how the engine idles, the injector is good. if you dont hear any difference, plug it back in and wiggle the connector a bit. if idle smoothes out, you may have a bad connection or bad injector. do the same with plug wires, but beware of high voltage. they can bite HARD.
If you are losing coolant, verify its not leaking by placing a large piece of cardboard under the car when you park it at night. if its not leaking look for white smoke out the tailpipe. you can also remove the spark plugs and shine a light inside each cylinder. if its nice and clean and shiny, you are burning excessive coolant and probably have a bad head gasket.
Any other questions lemme know =)
there is usually a pretty good seal between the plugs the the cylinger head, so unless the oil was somehow getting inside the plug wires, i dont think the valve cover gasket would be the cause for misfiring.
the easiest way to determine a dead or weak cylinder is to eliminate each contributor (fuel and spark) one at a time. if memory serves, you have the 3b engine with Electronic Fuel Injection (EFI).
Check to be sure your cold start injector is plugged in and functioning. if you suspect its not firing, remove it from the engine but leave it plugged in and connected to its fuel line. disable the engine from running by unplugging the wire from your coil to distributor and place the injector in a cup to catch the fuel. have a friend crank the engine over (you can remove the spark plugs to reduce strain on the starter if you want, but its not critical) and watch to see if the injector fires. if it does, and has a nice even spray pattern, its good. reinstall the injector and your plug wire and start the engine. unplug the other fuel injectors one at a time. if you hear a difference in how the engine idles, the injector is good. if you dont hear any difference, plug it back in and wiggle the connector a bit. if idle smoothes out, you may have a bad connection or bad injector. do the same with plug wires, but beware of high voltage. they can bite HARD.
If you are losing coolant, verify its not leaking by placing a large piece of cardboard under the car when you park it at night. if its not leaking look for white smoke out the tailpipe. you can also remove the spark plugs and shine a light inside each cylinder. if its nice and clean and shiny, you are burning excessive coolant and probably have a bad head gasket.
Any other questions lemme know =)
05-21-2009, 04:37 AM
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Well my plugs were all firing and my fuel injectors were all spraying. so im going to pressurize the coolant system today and do comepression tests in each cylinder and try to find out if it is a head gasket. If it is it looks like ill just have to fix it. If that dont solve the problem then ill let you guys know. im also going to get new plugs because i think for a while they werent always firing and are somewhat filed by fuel so ill just start taking things one at a time and go from there. thanks
05-21-2009, 04:40 PM
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something else you may want to check: i know this sounds weird, but make sure your oil cap and dipstick are securely mounted.f or some odd reason if you unscrew the oil cap or pull out the dipstick on theses cars while its running, it will stall the engine. i guess its creating a vacuum leak. if its not a tight seal it can cause rough idle.
05-21-2009, 05:42 PM
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something else you may want to check: i know this sounds weird, but make sure your oil cap and dipstick are securely mounted.f or some odd reason if you unscrew the oil cap or pull out the dipstick on theses cars while its running, it will stall the engine. i guess its creating a vacuum leak. if its not a tight seal it can cause rough idle.
