1997 Pontiac Grand Prix Swaping motors?

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WIHUNTING2369
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  • 4 POSTS
Engine Mechanical problem
1997 Pontiac Grand Prix 6 cyl Two Wheel Drive Automatic ???? miles

My son is dealing with swaping motors out he is going to put a 3.1 engine from a 1994 gramd am engine and trans to put in a 1997 Grand Prix. He and his buddy said they should switch no problem. I was a mechanic for about 10 years and i know how much work this involves. (he will find out) lol. I am wondering if you know if these will transfer over ok or wiill there be alot of issues with the change over? I get stuck helping with this. Fun Fun. Thanks for your help.
May 4, 2009 at 5:10 PM
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MMPRINCE4000
  • ✓Experienced Mechanic
  • 8,548 POSTS
If you are swapping like for like i.e. the GP had a 3.1 and you are swapping another 3.1 in, then the motor mounts and mechanical should be straight foward.

Having said that, you are swapping an OBDI engine into an OBDII car, that is a BIG problem. In 1996 all cars were required to upgrade to OBDII PCM's.

The wiring is completely different and that is where you will have the most problems.

OBDII engines have different PCM's and different wiring harnesses'.

Your best bet would be to strip 94 engine to longblock and put everything else from 97 on it (if 97 is a 3.1). Even so, you may have connectors that will not fit or there is not a sensor in the 94 for it.
May 6, 2009 at 4:45 AM
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