most likely its the tranny. could use a fluid and filter change or could be more serious.
What is the difference between overdrive and drive on a1991 Pontiac grand prix
If your Pontiac runs a 700r4 gm transmission you have stripped a reverse input shell. The transmission needs to come out for repair.
Your 1996 Mercury Grand Marquis may need a new transmission or something as simple as transmission fluid.
The transmission is kaput. Time for a rebuild.
inspect the upper motor mount
Idle speed too high.
no their not front wheel drive you must be thinking of a Pontiac grand am or a grand prix
drive cycle for 1998 pontiac grand prix, 3.8 engine, no super charge?
The Pontiac grand prix became front wheel drive in 1988-present. Before '88 it was rear wheel drive.
transmission is gone.
Brakes locked?
No, the Pontiac G8, which is the Grand Prix replacement is, but the Grand Prix hasn't been rear wheel drive ever since the 70's.