Vortec Intake Manifold Gasket Problems

[PonyKiller87]

Just finished doing a complete overhaul on the vortec 454 in my plow truck. Did everything from the head gaskets up. It was using a small amount of coolant before all the work which I knew was the intake gasket as its a common problem on the vortecs. Kilpatricks recommended a fel-pro gasket set that has updated intake manifold gaskets. Installed the new gasket to the torque specs in the GM service manual(first pass at 22, second pass at 30 ft lbs) And the damn thing leaks bad, way worse than it was before. Its dumping coolant into the lifter valley into the oil.

Is there a trick to putting these things on? I read that most leaks are from over torquing the bolts and breaking the gasket. I don't think thats the issue being that it was done with a torque wrench, by hand, per the book.

I'm planning on taking it back off some night this week, taking a look at the gasket. The old one that I replaced you could see where the gasket blew out around the front coolant port. I'm thinking if the new gaskets still look ok, just RTV the crap out of the coolant ports and put it all back together again?

Any one have any advice here?

[juicedimpss]

i thought those were supposed to get torqued in inch/lbs if my memory serves me correct.

[Car Guy]

I was thinking the same thing but this is what ALLDATA shows......


Tighten the bolts in sequence to 30 Nm (22 ft. lbs.) .
Re-tighten the bolts in sequence to 40 Nm (30 ft. lbs.) .

[PonyKiller87]

Thats exacly what we did and it started leaking within the first 10 miles when we took it out for a test drive.

[BAD LS1]

Remove Mark IV, install L92 /problems.

[PonyKiller87]

Yeah thats not really an option.

[BadAzzGTA89]

You check the heads? are they a lil warped??

[PonyKiller87]

I didn't take them in, just cleaned them up, replaced the head gaskets and put them back on with new ARP bolts. Everything looked like it seated nice and flat and there didn't apear to be any problems.

Before I take anything apart Im going to do a compression test on it again, hoping to just take the intake back off and replace the gaskets again.

[Sleeper Sierra]

the gasket probably wasn't lined up correctly.

[PonyKiller87]

Its pretty hard to line it up wrong, it has tabs that slide into slots in the head gaskets. That pretty much olds it in place, everything looked good and was lined up right, then the manifold was dropped on. Even if it was off a little the openings in the gasket are a little bigger than all the ports so if it moved a little in any direction it should still seal up the ports.

[Monstr913]

maybe u should have put it on yourself lol

[brotherbenn83]

Thats exacly what we did and it started leaking within the first 10 miles when we took it out for a test drive.

You mean you torqued it to 30 FT-LBS or IN-LBS??? If the latter, then you are severely under-torqued.

[brotherbenn83]

Did you get an intake gasket set for a 5.7 instead of a 7.4???

[PonyKiller87]

Did you get an intake gasket set for a 5.7 instead of a 7.4???

Yes I am a complete retard and didn't realize that not a single hole lined up, but figured it should work anyways..... Are you serious?:chair:


It got torqued to 22 FT LBs then 30 FT LBs as the book says.

[Anakonda69]

well we know it shouldn't be a torquing issue cuz i kept my handles clear of any bolts that had torque specs. lol

[brotherbenn83]

Yes I am a complete retard and didn't realize that not a single hole lined up, but figured it should work anyways..... Are you serious?:chair:

Hey you never know. After all, you're the retard who made his car more broken by "fixing" it.:durr

[PonyKiller87]

Took it all apart, looks like it was a combination of a few things. Intake manifold wasnt perfectly flat, its old and has some pitting on the gasket surface, and if you look where the rubber part of the gasket hits the intake around the coolant ports all 4 of them have 1 corner where there is very little surface for the gasket to seal.

Used a long body sanding block to clean up / flatten the surface of the intake. Added a small bead of RTV to both sides of the gasket along all of the rubber stuff. Reinstalled and torqued it all down again. Let it sit last night to make sure it all seals up good before I go putting the upper manifold and everything else back on. Should have it back together and fired up tonight.

[Anakonda69]

hurry damn you.