M,
I've recently noticed something similar on my UK spec 1999 (2000MY) A6 Avant
1.9 Tdi SE.With my foot off the accelerator pedal and turning the wheel to the left, there is distinctly more noise than I have been used to. It's a kind of vibrating sound and I've noticed something similar when I hit a dip in the road.
My A6 has 61,000 miles on the clock so this could well be a similar problem.
I jumped to the conclusion that the wheel bearing might be on its way out. Can anybody else confirm that this might be the case?
I will take it to my local independent VW/Audi specialist, Autotechnik, Southampton, to look at it I think. Mine is still under an Audi Approved Used Warranty so whatever needs replacing should be covered.
Cheers,
Steve