Any known problems with 3.1s?

[2.8 Grand Prix]

I am in the process of getting a 3.1 for my '88 Grand Prix. I was wondering if there are any problems with the 3.1 motors that I need to be aware of before I do this swap? I don't know if this helps, but the motor I am looking at is a '94.

[Superdave]

what's the 3.1 coming out of?



they're pretty solid when left stock, just the typical wear items like the timing chain and gaskets are what i'd worry about.

[2.8 Grand Prix]

It's coming out of a '94 Corsica. It has 146,000 miles and comes with the tranny. All for $150!

How to replace the intake gasket, do you have to take the heads off?

[robertisaar]

94 corsica? that should be a 3100, not a 3.1

3.1 = LH0 made from 1989-1994
3100 = L82 made from 1993-1999

[2.8 Grand Prix]

94 corsica? that should be a 3100, not a 3.1

3.1 = LH0 made from 1989-1994
3100 = L82 made from 1993-1999

Whith what you are saying, being a '94 means it could have either a 3.1 or a 3100.

[2.8 Grand Prix]

what's the 3.1 coming out of?



they're pretty solid when left stock, just the typical wear items like the timing chain and gaskets are what i'd worry about.

When changing the intake gasket, (I assume that's what your meaning), do you have to remove the heads?

[robertisaar]

in 94 the only vehicles to get the 3.1 were the cavalier and lumina. possibly the sunfire, but i'm not sure on that. everything else was a 3100. the cutlass supreme got them in late 93.

EDIT: to change the LIM gasket, no you do not have to remove the heads.

[2.8 Grand Prix]

Ok, then why does my friend's '96 Corsica have "3.1 MPFI" emblems on the front fenders?

EDIT: Thanks for the info.

[Superdave]

it's a 3100 and i'm not sure of the mounting differences but it's going to take some work to get that to work properly.


The good news is that it'll probably run ok on your old 2.8 injectors and tune.

[2.8 Grand Prix]

So what you are saying is that this 1994 Corsica 3.1/3100 isn't going to fit without some modifications?
EDIT: I need to know now because I need to call the guy with the corsica before I go to work!

[Superdave]

Correct, it's a gen3 engine. Your 2.8 is a gen2.

you will need to swap over to your 2.8 injectors, adapt the fuel lines and move some stuff around in your wiring harness.

you can re-use the old 2.8 exhaust manifolds, but you'll need to find a throttle cable that will work. The corsica one might fit, that's the one we use in the jbody swaps.

What's also un-clear is how your 2.8 engine mounts are, some stuff changed on the gen3 engines that require a new front mount to be made in a Cavalier.

it can be done, it's not hard. It will just take a little bit longer to do VS swapping to a gen2.


the good news is that it'll gain you about 30 HP over your 2.8.