Is my transmission shot ?
When I am doing 90 mph my car is doing 4000 rpm's. How many rpm's should
the car be doing at 90 mph. Yes I know that's fast but I do that on a clear road.
Thanks for the information.
Sounds like you've lost overdrive and TCC (torque converter clutch) lock in. A common problem with these GM transmissions. As a guide, my 2000 Grand Prix runs at about 1900 RPMs at 55 MPH. After a few minutes of cruising at a steady speed you should hear and feel the transmission TCC lock in. The engine RPMs will noticeably drop. If you're not seeing that, you've lost overdrive and TCC lock in. Hope that helps! Jim