Weird Shifting Noise / Vibration
2007 BMW X3 with M package
Here is the challenge .... it shifts weird. When we bought it we would be driving it along and hit a bump you would hear/feel something in the rear end that sounded like a gear disengaging for a brief period of time. After a few seconds it would reengage and go on about its merry way. Never paid much attention to it because it never got any worse.
Today though we had to climb a really steep hill. In auto it felt like the trans was slipping but it sounded like it was further back, maybe in the rear end. I changed to manual hoping to control it somewhat but to no avail. It literally felt like it was searching for a lower gear and not finding it but it kept climbing. On the way down the hill it was fine.
I then took it out on the highway and stomped on it it get around someone. The same thing happened. It felt and sounded like it couldnt find whatever it was looking for but it did accelerate. Normally driving doesnt cause any of these symptoms, its only when its trying to accelerate abnormally or is under some heavy stress like climbing a hill.
I had a guy tell me that all M series vehicles were like this due to the way they made the rear end but I had an M3 and dont remember it having these kinds of challenges when climbing hills.