How many miles are on you car? Did your check engine went on? Have you changed the transmission fluid recently? When driving do you feel like transmission slipping while shifting to higher gear? From what you said I don’t think it is a computer. I would ask the mechanic specifically. This or that does not do any good for you. If he says that this looks like mechanical problem I would try to change the Trans fluid and the filter (it is in case you haven’t done that recently). If filter is clogged up it may do that sometimes. Go to http://www.247-parts.com/
they have Red Line fluids best for your BMW. If fluid change does not help sorry but you maybe looking for new transmission. If you do I would check http://www.car-part.com/
I found transmission for low as $400.00 bucks. But you have to talk to seller and ask about warranty and returns since this is junk yard search engine all parts are from wrecked cars… Good luck.
1997 328I sport package
| RAID Steering Wheel | AA CAIS | AA Gen III Exhaust | SPAX Spring Kit | MEYLE Control Arms with Full-Metal Ball Joints and M3 bushings | BREMBO Rotors | Magnum Teflon SS Brake Lines | G2 Caliper Paint | M3 Bumpers, Door Moldings, Mirrors, Spoiler | M3 Double Spoke Wheels | M3 Motor Mounts | Stellar Keyless Entry | Euro Clear Tail Lights and Corners | DEPO Euro Headlights with Krypton Blue 6000k H1 Bulbs |
| Work in progress |