I bought a BMW approved pre-owned BMW 330i SMG. It had 50 000 km on the odometer and motor plan until 100 000 km.
This was 5 months ago. My problems started about 2 months into having it. Being a 330i, one would expect that it would be able to take anything you throw at it. Now let me state at this point that I am not a reckless driver, nor a driver that intentionally damage cars. I do however enjoy the performance for which I pay so much!
My first problem was intermittent with the gearbox not always selecting the reverse gear. This intermittent problem became more frequent, increasing to the extent that I had to be pushed out of my parking at the work place.
The BMW agent repaired this problem by replacing the gearbox management system. About a month after I got the vehicle back, I went to my friend who stays in the country. I thought this a great opportunity to test my car's top end speed. I went up to about 240 KM per hour when all of a sudden a warning light came on my console.
The warning light was and "F", then the gear light and then the gear in which it failed. I was unable to gear down or up, so it seemed to be stuck in one gear. I parked the car, switched it off and on again, but the problem persisted and I could of course not start the car again (since you have to be in N to start the SMG). After about 10 minutes, the computer corrected itself (or something's level dropped) and I could start the car again.
I took it back to BMW the next day and they rewired the electronics and installed the upgraded software. Not a week after that the problem resurfaced.
This time I had to wait two weeks for a new ECU (electronic computer unit) from Germany because they thought that the new gearbox management system was incompatible with the current ECU (something that makes sense to me, who works with computers every day).
Then, about 2 weeks later, the same problem. This time they went over the wiring and ensured that everything was in check.
Then again, 2 weeks ago. Today my car is at the agent once again and again a different technician is going over the wiring. Now I don't know why they don't let the same technician work on the vehicle as before. I also don't understand the communication between the technicians, if there is any at all. I mean, the wiring cannot screw itself up within a month from being completely rewired, can it?
Talking to the guys in the workshop this morning I realised that the gearbox is also driven by the oil pump (which assists in the selection of gears). Can it not be that my problem has something to do with rising oil temperatures and levels (since it only happens when I floor the accelerator)?