3100 lower intake leaking, tips needed.

[dodgerunner]

So looks like my lower intake is leaking under the TB side. Leaking out of the engine at least. Think I read this is a common problem.
Any tips on getting the coollant passage to seal well.
I redid the heads and intake a couple years (felpro set) ago due to a coolant leak into the #6 cyl.

Looks like I'll be pulling it again and want any feedback on getting a longer lasting seal.

[MATT2007]

I have had very good luck with the felpro gaskets make sure all of the old gasket is off of everything and you should be good to go

[3100 MPFI]

what year 3100? You might want to do the intake manifold swap if your car is a 1996 or newer, and then on top of that, you will probably want to get the intake gaskets from GM.

When I bought a set of felpro gaskets for the 3100, they were the older style. They crush and cause the coolant to leak.

If your engine has the large port intake, you will want the GM ones. They have the metal inserts that keep the gasket from crushing.

I have seen some solid metal gaskets (I think the new felpro ones are solid metal). I am not a big fan of those either seeing that they transfer heat more than the GM ones do. The 3100 was better than the 3.1 in the fact that the manifolds were isolated from each other. The upper intake on the 3100 does not get near as hot as the 3.1 does. If you put the metal gaskets in there, then you get more heat into the manifold, and lose some power.

Most people want cooler air going into the engine. That is why they do CAI. If you do the metal gaskets, you are kinda defeating the purpose.

[sil]

funny, i never thought about that, but i deffinatly noticed the old 2.8/3.1 monifolds got HOT and the 3x00 ones are cool.slighty warm to the touch
on my cars anyways, i allways wondered why lol

[dodgerunner]

Yes it is a 96 3100 so what is this manifold swap? Are you going to an earlier model of intake or what?

[3100 MPFI]

i sent you the PM. It is going to a newer setup.

Here is a pic of the intake swap on my 1996 Grand Prix 3100.


And here is a pic of the late 1999 3100 (large port) that I dropped into my 1988 Cutlass Supreme.

[3400-95-Modified]

I miss my pretty painted intakes.....

I gotta finish porting my 3100 plenum and get it painted!

[3100 MPFI]

mine look bad now. At one time, it was the looks that were important to me, but I finally got my head on straight. I don't care how it looks now as long as it works.

Runs CORRECTLY FIRST
Performance SECOND
Interior THIRD
Exterior FOURTH
Stereo LAST

[Rhedalert]

FYI those metal gaskets have a very thick rubber sealing gasket around every intake and coolant port. I really don't think that will transfer more heat than a plastic one.

[pontiac3100]

the reason the 2.8/3.1 gets hotter than the 3100 is the 3.1 tb has coolant lines going into it.
the 3100 does'nt

yea the latest felpro gasket set is the one, and once it's replaced no more lim leak.

[3100 MPFI]

the throttle body lines is not true. My 3.1 in my STE gets REALLY hot to the touch after only 5 minutes, and I removed those lines and bypassed them.

The upper intake on my 1996 Grand Prix stayed cool after 5 minutes and it DID have the throttle body lines.

IT is those gaskets.

And the felpro ones I saw only had silicone inserts, but too much exposed metal. Have not seen any other felpro ones.

[3400-95-Modified]

later 96 3100's have coolant lines going to the TB... I think it was only 94 and 95 that did not have these coolant lines.

[dodgerunner]

And the felpro ones I saw only had silicone inserts, but too much exposed metal. Have not seen any other felpro ones.

OK I have not seen these metal ones. The ones I picked up from Oreily's where the plastic with the inserts. Are these not any good?

What are the dealer ones like, are they the metal with inserts?

[3400-95-Modified]

The ones you got look just like the dealer ones, they should be just fine.

[pontiac3100]

the felpros i'm talking about is'nt the insert one's....
i never heard of those