Have any x3 owners experienced this?
2004 x3 3.0 automatic, sometimes bucks and surges at certain rpms (usually about 2700 to 3000, and seems to only happen in 4th gear.) It happens when accelerating, but load and incline do not have much influence, if any. 55,000 miles. Replaced plugs, but not coils. No difference. Tranny sensor, maybe?

Roamer
Not sure about 4th gear only, but there is a software issue w/accelerator in some years that results in acceleration hesitation and therefore some "bucking". The last I read there was going to be (should be by now) a software update by BMW to remedy this. I am not sure if this applies to your model year but it's worth a call.
jb

Thanks for the reply. I will check with the dealer for an update!

reprogramming the DME might fix it, but unless there's a bulletin or recall on your vehicle, they may be able to do it under warranty.

Roamer,
Had to reply. My '04 X3 3.0i has been experiencing the same problem for about 8 mos. and has been to the shop about 5 times now. At first BMW said they had never heard of this prob., and then like jamesb said, BMW said they could fix it with a new software update. I think we've had 3 software updates and I still have this problem. They also sent my "controller" to CA (I live in NC) for a week and still coudn't fix it. BMW has now admitted they are seeing this problem with X3s. I hadn't thought of it as "bucking", just called it hesitation, but when I saw the title of your post, I knew exactly what you meant. Very frustrating. If your's is still under warranty - get thee to the BMW shop immediately so they know you are having this problem and it will be covered even after your warranty ends. My 5 yr. warr. is up in August, but I'm going to keep bugging them until this gets fixed. Good luck, and let me know if you get your's to stop bucking. Diana

I seem to have a similar problem with my 04 X3 3.0

I just bought it so im still new to this whole warrenty thing...its covered by anyone that own the car in 4 year 50k right?

Diana and SubX -
Update - my dealer was able to fix this problem in one trip (although I did not ask about getting the repair covered, as I unfortunately read your posts after the fact). The problem is related to the engine management programming...under certain circumstances in this particular rpm range, the oxygen sensors send data to the computer that is misread as an alternatingly lean/rich/lean/rich fuel condition. The computer responds by adjusting the ignition timing, and the result is alternating hesitation, or when at its worst, bucking. The re-program cost me 123.00. It now drives flawlessly. Hope this helps....
Mike