Long story short. Had trans rebuilt in sons 97 grand prix. Evidently it's been acting up since rebuild aprox 5-6,000 miles. I didn't know it and son just gets in and drives. Sunday morning when it was cold I drove it and it reved high rpms before it shifted and shift points seemed wierd. After driving for a while it seemed to shift fine. When I got home and asked him about it he said it's done that since rebuild. Send him back to school in his mothers car. Fast forward to this morning I'm driving to work and as I leave our subdivision it revs to 4200 rpms before it shifts and the next shift seemed like it took a while too. Any ideas? Goes in wednesday to be checked but thought I do a little research first. TIA Pete

The TV cable may be broke. If it snaps it will act up. Its the other cable on the throttle body. Pull on it to see if it comes out.

The transmission in this car is either a 4L60E or 4L65E, neither of these use a TV cable. Sound like a seal leaking when cold, or possibly a sticking valve in the valve body. May have set a trouble code in the PCM. Did they clear the Transmission Adaptive Pressures (TAPS) in the computer after rebuilding?

The transmission in this car is either a 4L60E or 4L65E, neither of these use a TV cable. Sound like a seal leaking when cold, or possibly a sticking valve in the valve body. May have set a trouble code in the PCM. Did they clear the Transmission Adaptive Pressures (TAPS) in the computer after rebuilding?

Not sure if they were cleared or not. I take it to the shop tomorrow and the plan is to hook it up to the computer and pull codes if any and go from there. Thanks Pete

I had a 93 Bonneville with a similar problem. Turned out to be a bad shift solenoid...$385 parts and labor. Just FYI, this was after a Pontiac dealer looked at it and said I needed a $2,300 re-man transmission. You would think a dealership would have qualified techs, but that's not always the case.

I had a 93 Bonneville with a similar problem. Turned out to be a bad shift solenoid...$385 parts and labor. Just FYI, this was after a Pontiac dealer looked at it and said I needed a $2,300 re-man transmission. You would think a dealership would have qualified techs, but that's not always the case.

Thanks. I had all new GM shift solenoids put in with the rebuild. Doesn't mean one couldn't be bad though. Thanks Pete

It should have a 4T60E, unless it is supercharged in a 97, in which case it would have a 4T65E, It needs hooked up to a scanner, to see if the computer is commanding it to shift late. There are many variables on this trans that can cause this problem, anything from a bad sensor, solenoid, stuck valves or pressure loss. It could possibly be something as simple as a defective TPS on the engine. Is the "service engine soon" light on? You may have to leave it overnight at a shop, so they can hook it up to thier scanner when it is cold when it acts up.

Another thing, you could have a bad tps, and not set a code, as long as it stays within the peremiters set by the computer, which is around .5 to 4.5 volts, it could be showing say 4 volts at 1/4 throttle when it should be only showing about 1 volt, but it is still with-in that .5-4.5 range, and won't set a code.

It should have a 4T60E, unless it is supercharged in a 97, in which case it would have a 4T65E, It needs hooked up to a scanner, to see if the computer is commanding it to shift late. There are many variables on this trans that can cause this problem, anything from a bad sensor, solenoid, stuck valves or pressure loss. It could possibly be something as simple as a defective TPS on the engine. Is the "service engine soon" light on? You may have to leave it overnight at a shop, so they can hook it up to thier scanner when it is cold when it acts up.

I am leaving it at the shop tonight in hopes that it will act up tomorrow morning. This morning it didn't act up, must know it's headed for the shop. Pete

No codes and of course didn't act up at the shop. TPS where is that and what is it? Sorry for the stupid question. Pete

TPS=Throttle posistion sensor. It is on the throttle body at the oppossite side of where the throttle cable is attached.