2008A6

Thought i'd see if anyone has any other ideas or experienced the same..
My A6 has a very slight vibration that i can feel in the steering when i hit around 70mph. I started feeling it with my summer 19in tires (assumed it's balancing or bent rim), but it's the exact same with my stock 18in setup that i just put back on.
I thought for sure it's balancing..took it to the dealer recently and they said they road-force balanced the tires, but it made no difference and that it's prob some slight bending of rims.
I'm not too convinced since it was the exact same vibration with my summer setup. The 18s definitely did not have this issue before i took them off last time.
It seems unlikely that both sets of wheels could be unbalanced in the exact same way, with the exact same effect?? What else on the car itself could be causing this (maybe from potholes in NY/NJ), if not tires?
Once i felt that there is a vibration, it's starting to annoy me because i'm focused on it when on the HWY. Car has 25K miles. Thanks-

kemer1

Pretty much anything that rotates can cause those kind of vibrations. Anything from brake rotors that aren't balanced, to issues with drive axles etc.

triplecore

Do you live in an area of snow fall? There maybe frozen snow inside the rim which is causing the wheels not balance. This happens on my Audi and more significantly on my Lexus SUV as the factory 18 inch wheels easily allow snow to get inside from the backside of the rim.

2008A6

hmm..i didn't think of rotors being unbalanced..
Only problem is if i take it back to the same dealer, they will just say i have bent rims, which i dont believe is the case.
Would vibrating rotors or axle issues be covered under warranty?
Maybe i'll take it to another dealer to check for other possibilities.
Thanks-

The G Man

Have your dealer check the front wheel alignment?

05A632

I have the same vibration at the same speed. I attribute it to my stock pirelli's with 52k. Having new tires installed this weekend so my fingers are crossed it will correct the problem. Either way, report back here with your findings.

2008A6

I asked them about that but he said that wouldn't cause vibration, and the car steers straight.
But i could certainly see how it could be an issue if the front tires are not rolling perfectly straight..

scooter80

Slightly warped or unbalanced rotors will cause this all day long. Won't feel at lower speeds. There is almost always a slight drag with your brakes, so if your rotors are warped, the drag will start and stop with every revolution, causing a "vibration." And this will usually be felt during breaking as well, but if its slight, heavy braking may negate the effect.