I have 1995 Audi 90 with the 12V V6. I bought the car used 4 years ago and I haven't been able to diagnose this problem yet.
The problem appears mostly in highway driving on level road. The valves seem to be very happy to just clatter and ping away at just the exact throttle required to just maintain my speed. It seems most noticable above
60mph and seems worse at higher speeds. Just a hint more throttle to give an almost inperceivable acceleration and it very quickly and sharply get worse and then stops pinging.....until the car speed catches up with the throttle again and guess what, pinging. The same happens with just a hint less throttle. Again, with an almost inpercievable decelleration and the pinging stops....until the car slows to the throttle. This is all within fractions of 1mph. But, it's loud enough and disturbing enough that I'm always having to adjust the throttle away from a constant speed, just a whisper, to keep the valves from clattering away.If I crest a hill, just as the engine load changes from pulling up the hill to coasting down the other side the pinging appears.
If "crest" a dip, same deal. As I go from coasting to pulling up the next hill the pinging appears.
Are the knock sensors suppose to alert the CPU to this and correct it? Could it be a bad knock sensor?... or would it be worse?
Any suggestions?
Gene