MosRS4

Finally got around to it...brought it into DCH and went on a test drive with Miguel (service forman I think) since it only happens at 80-90mph and they don't want to be driving customers' cars that fast (at least not admittedly) Seemed like a really competent and good guy. Well, he ordered and replaced the rear differential under warranty and now it runs like it is supposed to! Something was just out of spec/balance and causing the problem. So if you have this issue, make the dealer check it out/replace whatever they need to - can't imagine how much that would cost if out of warranty...

BTW, I know alot of you have had bad experiences at DCH but they were above average versus other dealerships in terms of what I have encountered across brands(BMW, MB, Audi, Porsche). They also gave me a loaner without giving me crap (I didn't buy the car there).

Peace

LIRS6

Did it sound a bit like tire tread noise ..or like a b-17 flying around you?

Eric - The Red S4

Glad it fixed yours. Didn't fix mine. :-((

MosRS4

Haven't had too many b-17's flying near me but yea, very loud tire noise/humming that starts at 80 and seems to go away at 90 (or at least more drowned out by other noise at that speed or higher)

I took a longer ride on the highway and to be honest, it is definitely better but it is still there. Will take it back to see what else might be going on.

LIRS6

reference to the B-17 was because it sounds like a droning noise - like the noise a blimp's engines make. In my case it is purely related to speed, not rpms.

onrails

sounds like the front diff or driveline to me... 80 mph is the trigger speed.

MosRS4

Go to the dealer and request that the chief service tech/forman ride with you to experience it and try to get it fixed under warranty.

I was guessing it was the shafts or something but definitely in rear. If it was the front, would probably feel it in the steering wheel when you hit the trigger speed.

GL