Engine compatibility

1991 BUICK LESABRE
180,000 MILES • 3.8L • V6 • 2WD • AUTOMATIC
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JEFF HUMPHRIES
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  • 1 POST
I pulled the locked-up 3.8 liter V6 stock motor out of my 1991 Buick Lesabre and have a friend willing to give me a 3.1 liter V6 from a 1992 Buick Regal. I'm trying to find out if the 3.1 liter engine would mount right up to the stock transmission in the 1991 Buick Lesabre or if I'd have to change the flywheel or anything.
Aug 30, 2019 at 12:17 PM
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ASEMASTER6371
  • ✓ASE Certified Mechanic
  • 52,796 POSTS
  • ASE Certified Mechanic
Good afternoon.

The answer is yes and no.

The engine will fit but not be the same. The 3.8 and the 3.1 are different engines. The engine harness, all the sensors and the PCM are different.

It would require a complete wiring harness to make this work.

I would suggest getting the exact replacement. That would make it an easy drop in for you.

Roy
Aug 30, 2019 at 12:32 PM
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