when the car is travelling above approx. 80 km/h the autogearbox "locks up" (actually it's the torque converter). Once this happens a rumbling noise that follows the speed of the car starts - it not too loud but it gets rather annoying after you hit 180 km/s and up. It happens in both 3. and 4. gear once the "lockup" occurs. Besides that, the transmission is working flawlessly. Does anybody have a clue to what's happening - and hopefully a cure.

It's a 3.6 V8 from 92 with 145 tkm's on the meter.

Kenn Roland