4t65 problems

Hello all! I also posted this in the Grad Prix forum, I apologize if this upsets anyone. I recently purchased a 2001 Aurora 3.5, but the overdrive does not want to engage. In "D" at speeds when it is supposed to engage, I hear a dull whine and thats it. Selecting "3" eliminates the whine but no overdrive (of course). The fluid is at the correct level and does not smell burnt. The tranny shifts perfectly - its responsive and smooth. Im thinking torque converter is not locking up and might need replacement. Any ideas?

Or it could just be the TCC itself, not the entire torque converter unit. No?

I was afraid you would say that...

If I rember correctly.... The TCC will Lock up in 3 as well as D.... Put it in 3... drive it around (say to 55mph)... look at the RPM's of the engine. Then tap the brake (without letting up on the gas).. not enough to start stopping, just enough to turn on the brake lights. If you see the RPM's go up around 3-400 then the TCC is working.

Probably something wrong with a sensor, since they are computer controlled. Take it to a shop and have them scan the tranny computer for trouble codes... As tranny codes usually don't set off the check enging light.