LIM replacement - Again!

[joeld]

Almost 2 years to the day I've got to replace gaskets. Looks like a small coolant leak at rear just behind to dist plug area. Damn I do hate that, appears the Silicone form-a-gasket let go. What are you guys using on the end of the intake?

 

Joel

[slick]

Wait, what engine is this?

[joeld]

Sorry about that! 1995 Grand Prix, 3.1

 

 

Joel

[Crazy K]

you should only use FEL_PRO's PERMADRY gasket. no other. the cheaper gaskets have a short service life due to crappy design.

 

if you can wait a bit... rockauto has the best deal on it.

[joeld]

I agree 100% with not using cheap gaskets, just not worth the risk. Last time I did use Fel-Pro, This is what I have used for many years. Only the end of the intake is leaking.And from what I've seen, this sealing area takes the silicone type of tube sealant. What is the preferred type here. Thanks

 

Joel

[RYS]

I used Permatex Ultra Copper silicone.

 

 

It's good to 700 degrees. Make sure you use alot on each ridge!

 

I used a Fel-Pro kit when I did mine. I have no leaks and coolant is staying right where it should.

[joeld]

Thanks guys for the replies. Last time I used Permatex Black. First time this has ever failed me. Leaning towards trying the Great stuff.

 

Joel

[Crazy K]

I should be clearer. I recommend AVOIDING even the basic fel-pro gasket, it too is inferior. if you pull your intake, you may discover this yourself. I've pulled the intake off of a bad 3400, and even though gaskets were relatively new and were FEL-PROs, they were already about the fail at the coolant ports.

[Chancho]

GM Intake gaskets all the way, they redesigned them and they even come with new bolts as the service manual says to use

[joeld]

Thank you. And I will look at the GM gaskets. That is what I usually use. A little more money sometimes, but you get what you pay for. And you were clear there CrazyK on the Permadry being better. Good info.

 

Joel

[mfewtrail]

I use Permatex "The right stuff" gasket maker on the corners of lower intake manifolds. It sets up quickly and forms a rubber gasket. It's not too bad to clean up the next time you have to open up the engine either. The biggest mistake most people make on the corners of an intake manifold is using too little sealant. Lay a thick bead on there and you won't have any issues.

[SigEpCutlass]

You should use the Felpro Permadry gaskets or the revised GM gasket set. Don't use anything other than those unless you enjoy doing LIM jobs on a regular basis due to failures around the coolant passages.

[Brian P]

the perma-dry ones are the metal gaskets, with the molded rubber seals, right?

[Crazy K]

the perma-dry ones are the metal gaskets, with the molded rubber seals, right?

correct!! use nothing less.

 

personnally, the 3.1 mpfi ones are paper and don;'t seem to have probelms.... why couldn't the 3x00 gaskets just be paper?

[Brian P]

the perma-dry ones are the metal gaskets, with the molded rubber seals, right?

correct!! use nothing less.

 

personnally, the 3.1 mpfi ones are paper and don;'t seem to have probelms.... why couldn't the 3x00 gaskets just be paper?

 

All problems and failures aside, the 3100 LIM gaskets do a good job of shielding the intake manifolds from heat transfer thru the head and up. Whether or not that was the reason for that design I don't know.