94 Pontiac Sunbird Transmission problem

Wondering if someone recognizes this issue -

I have a 94 Pontiac Sunbird w/automatic transmission, 156K on drive train. Generally, the car runs excellent, I've had it since new. However, in the past month a problem has developed. Sometimes when I slow down for a stop sign or red light(after the car has warmed up), the car seems to vibrate a lot and more often than not will stall. I can start the car again no problem, but once I put the car into drive, it stalls again. If I let the car sit long enough, maybe 20 or 30 minutes, I can start the car and drive away without symptoms.

Now, I used to drive the car all the time, but for the past 6 months it has been 'retired', only being used to get me to work and back (about a mile one way). I can get to work and back no problem, it seems like the problem appears if I drive the car for longer than 20 minutes. I haven't taken the car to a mechanic yet (I plan to), so I was just wondering if my problem is the transmission. It sounds like you have a sticking torque converter lock up (or TCC) solenoid in the transmission.
The computer controls the torque converter clutch in the transmission with this solenoid. Sometimes the solenoid will stick after prolonged driving at a higher speed and not allow the torque converter clutch to disengage. This basically has the same result as coming to a stop in a car with a manual transmission in high gear and not depressing the clutch, the car shudders and stalls. After the solenoid cools down a bit it will usually allow the torque converter clutch to disengage again.

Normally the transmission side pan is removed and the solenoid can be replaced with no need for major work to the transmission. But on a ten year old car with over 150,000 miles you can never be sure what you’ll find until you get in there. It’s been awhile but I think I charged less than $125.00 parts and labor the last time I replaced a TCC solenoid.

My specialty is in engine performance so maybe Transman or someone else can give you more information.

Hope this helps There should be a square plug located on the top side of the transmission on the dirvers side. This should have four wires to it. This plug locks the TCC. Unplug it for a temporary fix, it will allow the transmission to contiue to work, it just won't lett the TCC lock in. The one in my truck has been unplugged for almost 10000 miles. You can do as broughy84 suggested to see if the problem goes away. But be aware that on a ’94 the check engine light will most likely come on and the computer will set a quad driver code. Like venturi said, the problem is going to be the TCC lockup solenoid. This is a common problem in these transmissions. The only other things I can add is to make sure, when you buy another solenoid, I would buy it from the dealer. The reason why is that when the dealer sells it, it comes with the solenoid AND the harness as one. If you buy one from someone else, you are going to end up cutting and splicing wires. The hardest part of changing the solenoid is getting the side cover off. Some vehicles are easier than others.

As far as unplugging the solenoid, you can do this, but ONLY TEMPORARY. Running it without the TCC lockup will overheat the converter and reduce the life of the converter and transmission.

Good luck



transman Agree with tansman and if you take a tcc selenoid from jobber sometimes you take the chance to have a selenoid with the resistance different from the original wich could cause failure in pcm.