[speedmaster1234]

I wanted to post my experience with my 2008 335xi coupe and the resolution so it may help people with a similar problem. Scroll to the end if you just want to see how I was able to remedy the vibration problems. IMPORTANT PARTS IN BOLD Read through to see my experience with BMW / local garage / and private foreign auto mechanic.

I started feeling vibrations in my car from the wheels which seemed to be focused on the rear right tire. The vibrations got worse, and were then accompanied by a loud rhythmic hum that reminded me of riding a mountain bike with a bent rim that rubs on the brake pad on every rotation - but magnified to the size of car. Then I noticed my back right tire was down to 25% tread while the back left was at 50%. Brought the car in to BMW dealer, and was advised to get new rear tires and an alignment.

Had the new Pilot Sport 2 tires put on (at my neighborhood garage) and scheduled an alignment at a foreign auto specialist - more on this later.

The new tires didn't change anything, problem worsened. Brought the car back in to BMW after advising them (thanks to e90post) that it could be an issue with the bearing.

BMW CPO replaced the bearing and the hub. I got the car back and the noise was gone, but the vibration was still there.

I called BMW and told them that there was still a problem (I also had 2 fuel system related breakdowns that required 2 trips to BMW instead of one this same month) but I would not bring it back to them, I wised up and brought it to a private foreign auto mechanic and had a full inspection done, alignment, and balance...

Here is what I know now - Vibration feel in the wheel and the pedals is often linked to imbalance in your front wheels, vibration in your seat is often linked to the rear wheels - all of my wheels were out of balance and after picking up my car it feels great - no vibrations.

BMW dealership will not necessarily diagnose problems with your vehicle. At no point after the BMW dealer had driven my car 4 times with the issue did they propose tire balancing, and only after I read about the bearing on e90post and requested it did they replace that. I'm still developing my auto savvy but wheel balance is the most common cause of vibration (it even said so on the car diagram on the counter of the private mechanic...) I was also out of alignment and they fixed that.

Moral of the story: Read E90post, NEVER assume the BMW dealer is going to think beyond the problem you have proposed, and don't let anyone touch your car who doesn't specialize in imports - I saved $20/tire to have my tires put on at my local garage but they clearly didn't address the balance issue either, nor did they mention need for an alignment.