I had the transmission slip and bang on mine a while back. There is a pretty long thread over on bimmerfest about this too. At about 74K I picked up a very faint slipping in auto when the RPM's were between 1500-2000 with very light throttle pressure in 5th gear. It almost felt like the car wanted to shift to 4th gear due to light pressure but couldn't make up it's mind. It eventually got worse and sometime got to the point where it was so harsh it felt like I was going to leave the rear end lying on the road. I took it into my dealer and of course nothing found. The next day, guess what, back again. They reset the adaptive values but that didn't help either. I ended up giving the tech the car for a week because every time it went it nothing was found and it was hard to get the car to do it because it would only happen in 5th gear at low RPM's. Eventually, they opened a PUMA case and they found the mechatronics was bad. Got the mechatronics replaced and all was back to normal.

As I said, this seems to be more and more of an issue as these transmissions get into 70k mileage.

 

This is by design btw... It's the lock up torque converter. The TCU does this to conserve fuel. If you don't want to conserve the fuel and don't want to the transmission to lock into fourth but it into 'Sport' mode. This prevents the early up-shifts.

 

I think your missing the whole point here. The idrive displays "transmission malfunction" and the car goes to 4th gear and stays there, and by stays there I mean even if I come to a complete stop, it takes off in 4th. Limp mode. Pretty interesting when your on the expressway and it locks in 4th so all the sudden your cruising at 4K. This may be how limp mode was designed, but there is no way you can convince me that the car should do this.

 

My car has 141,000 kms (87k Miles) and my tranny used to pulsate at 5th gear as well, it was way worse around the April May time frame where it would feel like someone rear ended me, that slowly got smoother to just subtle hesitations every 4 seconds, after the mechanic added 3 litres or transmission fluid and reset the adaptation, so far so good 4 days later. I'm crossing all my fingers knocking on every piece of wood, praying to the transmission gods that it's now fixed. We'll see in about a week what happens, especially when it's getting colder now.

 

My car exhibited this problem when my alternator went bad (drove it 20 miles to the dealership in Limp mode, it was scary!). After the alternator was replaced, it was back to normal. Hope you get the car problem fixed.

 

Indeed I did miss the point! But that makes sense since 4th is the lockup gear. Sounds much more like a low voltage/dead battery issue because the TCU is not sure it it will have the chance again to shift (or control anything) again before it looses power.

Yes, like this.

 

I just find it hard to believe that it would only happen from 4th to 5th if it was a battery/alternator issue, I've been wrong before though. But THANKS for the curse!!! I drove the wife's x5 to work today so she could take mine to the dealer and on the way home the alternator died leaving me stranded in 5 o clock traffic!

 

Dealer called this morning to inform us that they are putting a NEW transmission and mechatronics in my car. I guess patience pays.

 

Nice! Hopefully they don't botch the install or make you wait another month while they order hex bolts from Deutschland.

 

Car will be done on Monday, how does everyone feel about break in? It's a new transmission so I'm wondering if there are a certain number of miles I should take it easy on it?