Recently bought a 98 A4 with 2.8L dohc. It ran fine then all of a sudden one day it started missing and the check engine light came on. My daughter drives this car and lives 90 miles away, so she took it to the dealer. Dealer checked the codes and changed the cam sensor. Car ran fine for a few days, then the check engine light came back on. She took it back to the dealer and they discovered that the spark plug hole where the spark plug wire goes was full of coolant. They had previously removed a lot of dielectric from that sparkplug boot and when I talked with the technician he said someone was trying to get that cylinder to fire. I wasn't quite sure what he meant at first until I got the car home and looked at it myself. There is indeed liquid flowing from somewhere into the sparkplug hole. The car runs good as long as you just feather the throttle. If you give it too much gas at once it seems to misfire (or backfire), stumble or hesitate. Compression is strong across all the cylinders at 150 psi. Anybody ever experience this kind of problem before or know of a defect in the Audi cylinder head that would cause this. Also, does anyone know where I can get a diagram of the water flow through the cyliner heads?

 

does it happen to be a cylinder on the driverside bank where the coolant reservoir is? if there is a leak under pressure possibly a cracked hose or tank then you might get coolant on and in anyone of those three cylinders on that side..

 

thanks for your response however, its on the passanger side, right bank, rear cylinder, # 3