I have a 1995 Saturn SL-2 with 115k Miles on it. I love the car and the great gas mileage (30-35 mpg). Like all Saturns of that time it has had the reverse slam disease since around 60k miles. I baby it when I put it in reverse to keep from tearing the transmission up because of this.
I now have a new problem. About 2 months ago, the transmission began slamming into all gears sometimes. The slamming seems to be worse in the evening and is either all or none. It either slams or does not. When it is slamming, the hits are hard enough to bark the tires or make you think someone has hit the car. Babying the accelerator by backing off or releasing the pedal to force the shift will prevent the tire barking, but cannot prevent the slams.
Now for the weird part occasionally the service engine light will come on and when it does the transmission suddenly shifts smooth as glass and continues until the car is turned off.
Here are my thoughts, the service engine light is probably activating a fail safe program in the computer that ignores most of the sensor inputs and just uses preprogrammed values. The fact that the transmission runs fine during that time would indicate that there is likely not a transmission problem causing this but rather the computer is getting faulty data and giving out bad commands to the transmission.
I have not pulled the computer code yet. I guess that is the next step.
The transmission shop wants to rebuild the transmission for upwards of $1000. I do not think that will correct the problem with the car.
Anybody got another thought about where to start looking?