My 1992 740 GL turbowagon was "Making a loud noise and wouldn't accelerate" according to my daughter. I'm thinking, maybe it needs the valves tuned (It's due). But sure enough, after driving it, I found it wasn't going to O/D. Checked on this forum, and had great help. Thanks for the troubleshooting of the O/D relay (I did have a couple bad solder joints, and got them fixed) and got the relay to function using the shifter switch :-) cause I heard it switching. Still didn't fix the problem, so did some troubleshooting and found the O/D solenoid frozen. Wouldn't respond at all. So rather than pay $207 for a replacement part online, I followed the tip about bypassing the solenoid ports by using a dremel tool to cut a channel between fluid ports (as per the picture on this forum). It was easy, and the car runs like a champ. Good advice and pointers from this forum, thanks!!!