I have a 1998 A4 quattro, it started a knocking sound in the rear left wheel area at road speed , it would do it in and out of gear, braking and accelerating. The sound would speed up as the vehicle speed increased but as i was taking it into a shop it stopped. It started again about 3 days later but came and went just as quick. Ive checked the wheel bearing, cv shaft, brakes, suspension, dif fluids, and nothing is showing problems. Any suggestions would be appreciated.

 

I also have a knocking from the same area so am interested what answers you get. Have you checked for a broken rear spring? The noise seems to be at wheel speed frequency but comes and goes. I replaced the rear shocks thinking it may have been them (at 155k miles they were due anyway). Now I have a driveshaft on order.

 

checked the springs today nothing broke, still dont know what the problem is.

 

the thing thats puzzling me is that it comes and goes, when its there it sounds really bad but when its not the car runs perfectly