Monster13

Recently became the proud new owner of a beautiful 2002 A6 4.2 Quattro, 140,000 miles and the price was just to good to say no. Overall for a twelve year old car Darlene is in pretty darn good shape, definitely the cleanest used car (especially the engine compartment) I have ever owned or even seen. There are three small noticable dents on the body, minor interior issues (leather cracked w/ small hole on passenger seat, dash cup holder broken, etc.....)Driver side window switch not working right......... Silly small stuff. The one concern I have is, after about 15 min of driving there is a distinct high pitched whining noisethat starts, the noise increase in volume as the RPM's increase, when the car shifts up the noise quiets and builds again as the RPM's climb. Naturally I am thinking loose belt, inspected the belt and it looks great, with engine running and hood open it seems the noise is coming from the bottom right (driver) side pulley or the belt is slipping right at that pulley. Tried applying some belt dressing and that helped for a few days but then the noise returned with a vengence........ It seems the pulley may be shot, or I am just barking up the wrong tree, I do know there is another belt (timing belt) that is covered up, could it be that one? Any advice or suggestions would be greatly appreciated..
One a side note, I sure wish I owned this beast of a machine back when there was no speed limit here in Montana USA.......... WooHoo good times

Kris Hansen

Ok, 2 things. 1, I'd make darn sure that the noise is coming from the serp belt, and not the cam belt. Do that by pulling the serp belt temporarily, and revving the engine. Do you know if the waterpump, pullies and belts were ever replaced?

I'd have to look at the engine layout to see what is down on that side.. on my old C5 it was the AC compressor.. not out of the question to have a bad bearing in that. See if you can snap a photo.

Monster13

I will check on the things you mentioned, get a pic on here for you, and the Serp belt does not look 12 years old but, I will investigate further. A/C I highly doubt, is cold here in MT now and I have not been using it..

Kris Hansen

Right, but the clutch has bearings in it, which allow the pulley to turn when the clutch is disengaged..

Monster13

Clutch? Are you still speaking about the AC? Cause if not I do not believe my particular A6 has a clutch. It has an automatic transmission.

Kris Hansen

Yes. The AC Compressor has a clutch on it.

Monster13

Looks like it turned out to be the ac compressor pulley, hearing were shot all to hell. Changed the Serp belt and the other pulleys as well. Seems to be doing great. Moving here soon, will take her for the first highway trip soon. Had to change out both O2 sensors as well.

Monster13

Bearings were shot...... Sorry

Kris Hansen

Cool, glad you got it sorted.