Yesterday I took the xi to work. On the way home I felt a slight wobble on the car like I had a flat tire. No flat tire at all. My wife told me this morning that the car was doing that again on the way to work. Seem to happen under hard acceleration at low speeds but she told me that she felt it only slightly at high speeds. The car is a CPO that expires on 3/24/09. I made an appointment with my indy BMW mechanic to leave it on Friday so he can check it out. With my limited (very limited) mechanical skills I came up with this list: Out of balanced tires Driveshaft? Transfer case? axle? I ruled out the power steering rack/box because it was replaced under CPO last January and the wheels are not bent. Any thoughts?
See if you can determine exatly what speeds you feel it. Usually if it is a low speed and then a multiple of that speed, it is tire balance. For instance, many people will complain about a wobble at 60, but not notice that it does it at 30 and 90. This is classic tire balance. If it shakes the wheel it is front, and if it shakes the body it is rear. It may have just lost a wheel weight. If you had tires mounted somewhere that you got a lifetime balance and rotate included, start there.
If its a wheel weight, then that would be great. I don't think the steering wheel was shaking so it would probably come from the rear. I am waiting for the better 1/2 to respond back to me so I can confirm that. I got the rear tires from Sears around February and the front tires were put on just before we purchased the car last year at this time. I'll just let my mechanic take care of it if its just a wheel weight.
She just told me that the lower the speed the more it wobbles and its not coming from the steering wheel (no shake, no wobble).
It seems to be only during acceleration as I drove the car for about two hours this morning. Since the weather wasn't too friendly this morning, I drove my wife to work then drove to work. It was very inconsistent. Happened at low and speeds around 60mph. I drove the car up on the curb in front of my house last night and used a zenon BMW flashlight and checked the rims from the back and couldn't find any bends on any of the wheels. I will just have my mechanic drive the car Friday so he can determine what the problem is. If its something small, then I have him do it. However, if its a big ticket item (driveshaft, transfer case, transmission, etc...) then its a trip to the stealer under CPO.