Mechanics

2.5L TRANSMISSION WILL NOT SHIFT OUT OF OVERDRIV

1991 Pontiac Grand Am • 6 cylinder 2WD Automatic • 92,999 miles

1991 Pontiac Grand AM 2.5L mileage: 93,000. My car has a 3 speed automatic transmission with overdrive. The overdrive kicks in above 45 or 50 mph automatically. When traveling in overdrive for a long period (half an hour or greater), the transmission will not shift out of overdrive when slowing down or coming to a stop and the car stalls. Upon restarting the car, (in neutral or park) the transmission is still in overdrive. In order to get the car out of overdrive, I have to rev the engine and drop it into drive (not good). Do you have any idea what might be causing this?
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2CarPros-Archives
October 20, 2010.



Your car has a lock-up torque converter in the transmission. It locks-up only in high gear. It is supposed to disengage at lower speeds. Yours is not disengaging. There is probably a valve in the transmission "hanging up". Having the transmission serviced with new fluid may help the problem. Next step, the valve body will have to be removed and cleaned.

Tiny
2CarPros-Archives
Oct 20, 2010.