I have a 92 325i with 70k miles (auto transmission). When driving cold the engine will rev but the transmission will not shift up. Also happens after car is warm then for a period of time. Sometimes the car will slip completely out of drive into neutral and periodically when I come to a stop, the car behaves as if it will stall. Problem only appears intermittently and local BMW dealer says tranmission is fine. Any ideas would be most appreciated.
