1994 Buick Century Overdrive issues

You lost me......... I dont understand when you say it will shift up into 3rd but wont shift down again. The it will go into OD if you cycle the key but wont shift up?

[quote:21aa43a6b7="2CarPro Jack"]You lost me......... I dont understand when you say it will shift up into 3rd but wont shift down again. The it will go into OD if you cycle the key but wont shift up?[/quote:21aa43a6b7]

It will shift into 3rd, no hill, no increase in throttle. Once in 3rd it will stay in third until you turn off the ignition. If you restart the car it will then shift through the gears back into overdrive but only for a couple of seconds and then back into 3rd. If the car is allowed to cool down completely, it will run in O/D for about 30 minutes and then it will shift back down into 3rd.
I'm sure its not good on the car but after it shifts down into 3rd I can turn the key on and off while driving and it will shift into O/D, again for just a few seconds and back down into 3rd leaving me to believe that its not a transmission problem. Any ideas? Thanks much!!!

That actually could be a trans problem or engine management. Either way have the PCM scanned for codes. If the trans is having a problem, it wont go into OD. On the other hand if the PCM thinks you are on the throttle it wont let it go into OD

Could it be a vacuume leak creating issues?

Does it have any driveability issues besides the shifting into OD? A vacuum leak would make it either idle rough or hesitate or something noticeable a far as the engine goes

The cruise control quit about the same time the O/D starting acting up.

It does idle weird at times, especially cold but for the most part the engine runs fine.

I know the cruise runs on vacuum as well, just running scenerios.

It sounds like its probably time for a trip to the shop, even though the repair will more than likely be more than what the car is worth.

I understand. But you might want to have the diagnostic done to be sure you arent doing other damage to the trans