1St jumping back into neutral HELP!!!
 

This just started and I have no idea why but when I slow down enough to drop back into 1st, intermittently upon acceleration, it revs up, of course, and then bang, pops into 1st and jolts. What is happening exactly and where do I start to look first?

Thanks

Sounds like transmission is screwed. Go get a shop to check it out.

Something not working right (sticking) in the valve body (mechatronic)?
I would try to change the oil, 3 times in a row to make sure to dilute enough to have new oil in there. Drive one week between the changes.

Mine was starting to do that intermittently (once or twice a month) and I did 3 oil changes with a week of driving in between, and now it is fixed.

search this forum for transmission slam and see if that is what is happening to you?

Thanks Guys!! I'll definitely work at flushing my tanny this weekend.

I have been talking to a couple mechanics already this morning who have worked on other vehicles and they say that dropping the transmission pan and replacing the filter and gasket while doing a tranny flush is important and while the transmission pan is down, rinsing the area with brake clean to rinse as much garbage out as possible is definitely hugely advantageous in cleaning out the transmission before installing the new filter and gasket and then putting good quality synthetic oil in it. Is this doable with the X5 transmission?

It is doable, and exactly what you should do. But one thing, I would not flush the trans. Only replace whatever fluid came out. Do not swap out all of the fluid in one shot. Shit can get "shocked", and you might have a complete trans failure. Also note filling procedure. Search here, search my name if you want. I did a write up on dropping the pan. 4.8is, but still.

Awesome!! I found your post including pics. This is definitely going to help me save a ton on not only doing it myself but also knowing that it was done right. I really appreciate it. Thanks.

So my buddy and I emptied the oil that looked more like used engine oil after about 10,000kms and refilled it with standard ATF 3. We took it for a drive to mix it up and then drained it again, then filled it back up again. Now that I have the filter and gasket, I'll buy some more ATF fluid for the final flush. I'm feeling a lot better about getting so much of the used oil out although I know it doesn't take much black die to turn any other colour dark. Once we drop the pan and replace the filter & gasket, I'll feel a lot better. I hope this solves my problems with shifting. I can't believe BMW does a flush and recommends keeping the old oil in the vehicle. That just makes zero sense to me. If I would have purchased the oil from BMW, it would have cost me $50/L. That is insane if you ask me.

Please make sure to use oil that is to spec. Some will say use the exact fluid that is in there, and I agree, but at least make sure you get the fluid that meets specification for your trans.