how to tell differance between 2.8 and 3.1

[White93z34]

i got a car in the shop now that states on the Vin that its a 3.1 and on the emissions tag that its a 3.1, however the intake plenum states that it has a 2.8, how do i verify which engine this car actually has?

for what its worth, its a 1989 Grand Prix LE

[geoffinbc]

3.1L was introduced in 1990. Replacing all previous 2.8L's.

So an 89 will still have the 2.8L.

[sharkey]

RE: how to tell differance between 2.8 and 3.1

the only way i know how to tell is by the egr. the 2.8l had a vaccume egr, were the 3.1l had a digital egr. now that doesnt mean a whole lot (engine could have been swapped and used the original ecm, meaning they would use whatever egr was on the car).

[TheProfessor]

RE: how to tell differance between 2.8 and 3.1

dude
how can the vin say it is a 3.1 when they didnt come with 3.1s that year
better make sure that bitch aint stolen and the vin plates havent been switched

[White93z34]

RE: how to tell differance between 2.8 and 3.1

the 3.1 was avaliable in 89'

VIN: 1G2WK14T7KF281216
Year/Make/Model: 1989 PONTIAC GRAND PRIX LE
Body Style: Coupe
Engine Type: 3.1L V6 FI
Manufactured In: UNITED STATES

[TheProfessor]

RE: how to tell differance between 2.8 and 3.1

yeah it was
i just checked
i was going on what betterthanyou said
they might have always just put a 2.8 plenum on it for some reason

[firechiken]

RE: how to tell differance between 2.8 and 3.1

Uh-oh. Better update the family tree!

[geoffinbc]

I guess I will have to. But all source I made the tree from say the 3.1L was a 1990 thing.

I have just found however that there is both a W and a T motor. Both the 3.1L and 2.8L were avalible during 1989

[geoffinbc]

Wait a tick. Was the 3.1L Vin T not the Turbocharged varient?
That I do have listed on the tree

[TheProfessor]

in 89 there was the 2.8 vin W the 3.1 vin T and the turbo 3.1 vin V
i have a book that has every engine that was in every car all the way back to 1980

[geoffinbc]

Yup just figured that out.
Fuck now I gotta fix the tree.

[geoffinbc]

Fixed.

3.1L now introduced in 1989

[White93z34]

so now that we verified the 3.1s existance. how do i tell whats what?

[geoffinbc]

Verify the VIn tag on the side of the block. T will mean it is a 3.1L

[RacerX11]

Also, the VIN T referenced the 3.1L aluminum head FWD engines, as well as the 3.1L iron head RWD Camaro engines. It can be confusing when ordering parts.

Marty