I recently went on a trip from Rolling Meadows, IL to Cape Coral, FL in my '94 Mitsubishi 3000GT, 1400 miles there 1400 back. She took the ride fine, never gave any problems at all.

However, when I got back. I stopped the car outside of my apartment, went inside and slept for a few hours. I came back out, the car had sat there for about 7-8 hours, and started driving to go pick my ex up from work. Well, as I started to go down the road I pushed down the accelerator and, when she tried to shift from 2nd to 3rd gear, the engine revved to red line and wouldn't up-shift unless I shift the car from neutral and then back into drive.

Now, if I turn the overdrive on the car off, it shifts just fine all the way up to 3rd gear. I haven't tried to get it up to fourth recently seeing as I'm driving on inner city streets and I don't want to stress the transmission too much without having an idea of what the problem is.

When I discovered the problem, I checked my fluid levels and noticed that my oil was next to none existent as was my transmission fluid. I took the car in, seeing as, as much as I love them, I build computers, not cars. They changed what little oil was there and put in new transmission fluid, flushing out the old. At first it seemed to help but then after awhile it started doing it all over again.

Any advice on this would be helpful as I know absolutely nothing about transmission system. I've thought about maybe just changing it out for a manual, but then, after some research, discovered it'd be cheaper to just go buy a VR4 with a manual transmission, AWD, and a turbo instead of buying a manual conversion kit for an SL.

Check the fluids again.

Sounds like the overdrive module.

Good luck its on the out side of the tranny.