Why would the intake have to be swapped? They're both 3.1's!

[ragejg]

Just double checking my garage's decision.

 

My 93 Lumina, originally equipped with a 3.1 MPFI and a 125-C tranny, is recieving a newer motor after the old one seriously crapped out at 130k...

 

The newer motor is a 91 Buick 3.1 MPFI, which was originally taken from a Regal, plugged into my 92 Lumina Euro's wiring harness, and mated to the Euro's 4T60... at 90k. That swap ran me $600.

 

That was 2 years ago. Well, since then, the Euro's body and subframe gave out, so the Buick motor, now at a paltry 105k, is to go into my '93.

 

$1100 quote? wtf?

 

Lots of the extra cost comes from the fact that this is a different garage doing this, but also:

 

I was told that there's a difference in 93 3.1's that has made an intake manifold swap a requirement... according to the garage, everything is kosher for a 91-92 or vice versa swap, but 93 is different. They sure don't look it.

 

I'm left scratching my head about this still, wondering if the information sopurces for the garage are thinking that the 93 3.1 is actually a 3100 SFI, which is not the case.

 

1993 is the last year of the 3.1 MPFI, correct?

 

Might I be having some un-necessary work done?

[94CutlassSLCoupe]

94 luminas and cavaliers still came with the 3.1 MPFI

 

The 3.1 MPFI is VIN T and the 3100 is a VIN M

[gp90se]

theres a plenum difference between 88-90 and 91+, not sure if 93 is any different.

[Guest TurboSedan]

i have never heard of a '93 3.1 MPFI plenum being any different than the '91-'92 plenum. '88-'90 plenums are different though as gp90se mentioned.

[1990lumina]

So just to verify for my dumb ass - my plenum in my 1990 Lumina 3.1 is different from a 91+??

[Guest TurboSedan]

yup. the '88-'90 plenum uses smaller bolt holes and larger bolts than '91+ plenums. the '91+ plenum have larger bolt holes and smaller bolts, but the holes are bigger because the bolts use a rubber sleeve around them. because of this the lower intakes are different as well.

[DaveFromColorado]

some shops will try to pull that shit on ya, don't let them, tell them to do the swap, without changing any parts, if they still have a problem with it, tell them to just physically swap the engines, and hook up the wiring yourself.

 

--Dave.

[ragejg]

Grr, this guy is definitely not the type of guy to take advice from "enthusiasts from teh intr4web" ...

 

Ahh well, I called my old garage, and they agree with you guys, but come to think of it, that motor does have the characteristic leak in that area, so the swap (1.5 hrs labor for removal of both and installation of one) plus the cost of a new gasket set really won't set me back that bad...

 

I guess I'll just look at it as a preventative maintenence measure, and maybe smile a bit knowing my intake is 2 yrs newer than the block.

 

 

Thanks, guys.

[gp90se]

just an fyi, a plenum from a 91+ will bolt onto an 88-90 lower intake with the new bolts