just to share my 2cents worth over the last 2 months that ive been experiencing.
Whenever the gear changes, it has a strong jerk, ie from first to second and second to third. Send to workshop and run diag and says its gearbox failure!!! ouch...
Then i told him to reset, after resetting, test drive, no difference.....so, chances are he is right...
Then, i told him wait, let me think...
Left the car at home for 2 days (not driven), then took it out to antoher workshop, to my surprise, there is no more jerk....perhaps the resetting works but it doesnt work immediately....
A week later, guess what, overheating...so, when open the bonnet, i see teh tarik gushing out of the expansion tank and the floor...
Send to workshop, now realised that there is already auto oil in my radiator and cause of it is the "heat exchanger" likely to have gave way but there is no way to check. To remedy, i have to change everything, radiator, all the hoses, expansion tank, heat exchanger, flush, auto oil again etc....the fortunately thing is that the coolant didnt get into teh auto transmission otherwise, need to chagne gearbox....
Moral of the story is that, go for the basic resetting first for the first part, also, if your car mill is below 150 K, dont listen to workshop to change gearbox as chances are slim but make sure u change ATF though.
Second, change your heat exchanger regularly perhaps every 50 K as it cost about RM500 only otehrwise, you will have to spend 10 times the amount assuming gearbox is not affected otehrwise, multiply that by another 15 times....
This is my first Beemer and i was rather surprise the nos of faults with the car as i hardly use it and yet problematic compared to Merc where mine W203 is problem free in the past 5 years!!! Thats the price to pay if you want to feel the drive....
cheers