Oil Pan Gasket Sealant

[Bob D.]

I'm working on the lower end of my '71 and was wondering if anyone had any recommendations for a good gasket sealant for the oil pan gaskets? I usually use Permatex, but was wondering if anyone had any success with other barnds or types of sealants.

Bob

[Timothy B.]

Re: Oil Pan Gasket Sealant

Bob,

On my 327 engines I used permatex ultra black silicone on the block then fitted the gaskets to the block then ultra black again to the oil pan surface. I also used a thin smear to both sides of the rubber end gaskets when I fitted them.

Be careful because this stuff will clog a oil pump screen if you are careless. I have no leaks, also consider the newer GM florelastomer rear main seal, check archives for discussion.

[Michael F.]

Re: Oil Pan Gasket Sealant

I use permatex right stuff. If you use modern fel-pro gaskets,theres really no need to use all that silicone. Installed right even the old cork ones don't need much silicone.

The water pump and timing cover gaskets just need a light coat of grease and proper tightening.

Intake needs a thick silicone bead on the front and rear of the oil galley. Use NO silicone on the intake gaskets.

The oil pan gasket only needs silicone at the crank and timing cover.

The main factor here are properly cleaned and degreased surfaces. And follow makers instructions.Thats how you avoid oil leaks.

[Domenic T.]

Re: Oil Pan Gasket Sealant

Bob,
This is one that every one does differently.

I think the advise you already have is very good and would like to add what I have seen go wrong with sealing gaskets.

When you use a sealer on thich gaskets such as pan gaskets , do not tighten all thr way or all at once initally or you will split the gasket.

I usually tighten moderatly, then let the sealer cure over night, then go for the correct tightness. This prevents the gasket from sliding to much under the bolts or screwscausing it to split.

The other thing is that it is a good Idea to keep the oil that you assemble the lower end from running on the gasket & sealer till the sealer cures. Thiss happenes when you rtotate the engine on the stand.

I know it takes longer to do but it saves the time of fixing a leak. I do mine bottom side one day and top side the next leaving them unturned while curing so oil cant run on the new gaskets & sealer.

DOM

[Dick W.]

Re: Oil Pan Gasket Sealant

#2 Permatex has always served me well. Make sure there are no dimples around the bolt holes on the pan and do not over tighten.

But then again, I have always heard that the only Chevrolet engine that did not leak oil is the one that has no oil in it

[Bruce B.]

Re: Oil Pan Gasket Sealant

I use Permatex #2, a non hardening sealer.
Not a silicone material.
I believe silicone is great for use on the ends of intake manifold to block sealing and a number of other applications. But on a gasket that can squeeze and move, as on oil pans,auto transmission pans, silicone is not my choice.

[Bob D.]

Re: Oil Pan Gasket Sealant

Thanks everyone for the good advice. As always this board is a wealth of information and help.

Bob

[Timothy B.]

Re: Oil Pan Gasket Sealant

I want to add something to this post, those cork oil pan gaskets are very easy to damage as Domenic posted. On my cars, I located GM NOS gaskets and they are VERY different then the cork. I believe you will distort the pan before the gasket squeezes out.

In any case, the silicone will give the gasket some rigidity after it sets up. Just a thin coat to clean surfaces to glue everything in place. Then again on the other side and snug the bolts. The silicone will set up and seal nice.