Originally Posted by Reddots89
i have the same problem with both of my seats. to my understanding there is plastic gears within the seat motor that break pretty commonly. they are almost impossible to find and if you bring it to bmw they only offer to replace the whole motor which i think was a couple hundred bucks. my advice would be to look up the gears online somewhere and try to tackle replacing the gears. i have dealt with mine for months now and pretty much got used to it though i would like to eventually fix mine.
WRONG! They are cable operated via a motor and 99% of the time the cable has a kink or has jumped off a pulley. You need to pull entire seat(s) from car and disassemble to gain access. There's a good DIY in the E34 section - try a search (in forum search for seat info)