Oil Leaking Through Manifold Bolts

4 SPEED

Well-known member
Joined
Jul 21, 2009
Messages
78
Location
New Jersey
I have a 74 and I keep getting oil around the manifold bolts.
I have tried all kinds of sealants including permatext and teflon sealer.
Even tried replacing the bolts.
Was going to try tape but afraid it my get inside the engine.

Thanks in advance for any input.

4 speed
 
I have a 74 and I keep getting oil around the manifold bolts.
I have tried all kinds of sealants including permatext and teflon sealer.
Even tried replacing the bolts.
Was going to try tape but afraid it my get inside the engine.

Thanks in advance for any input.

4 speed

All I have ever done is pull the bolts one at a time, blast GOOD carb cleaner down the holes a bit, blast out with air, then more cleaner then more air, until it is sanitary from any oil, clean the bolt super clean, put a good coating of the GOOD RTV silicone sealer by GE, and snug down the bolt, let dry overnight.....aggravating job...I know....:pprrtt::bomb:
 
I have a 74 and I keep getting oil around the manifold bolts.
I have tried all kinds of sealants including permatext and teflon sealer.
Even tried replacing the bolts.
Was going to try tape but afraid it my get inside the engine.

Thanks in advance for any input.

4 speed

buy some extra felpro intake gaskets and lay a bolt in a hole and draw around it. Then cut it out and trim and use that as a gasket, that will seal the oil issue.
 
I have a 74 and I keep getting oil around the manifold bolts.
I have tried all kinds of sealants including permatext and teflon sealer.
Even tried replacing the bolts.
Was going to try tape but afraid it my get inside the engine.

Thanks in advance for any input.

4 speed

buy some extra felpro intake gaskets and lay a bolt in a hole and draw around it. Then cut it out and trim and use that as a gasket, that will seal the oil issue.

I like this idea and will try it out soon.
Guess I am getting this problem because the gaskets in there now suck?
 
don't do it

I would advise against the small gasket under the bolt head. The bolt must stretch (microsopically) to keep a load on the gasket. The gasket seals because it is compressed between the head and mainfold. Putting a soft (gasket material) washer that will , for lack of a better term, squish under the bolt head will let the bolts loosen. The little gasket will see the same bolt clamp load in pounds as the big gasket.

It may be more work but Gene's method will give you clean surfaces that the sealer will seal.

Grampy
 
I find that rather odd.

Maybe a question before I answer. Were the bolts zinc plated and are they corroding ?

Bolts are SS and brand new.
I have tried all kinds of sealants with no luck.
I probably will use gumout to clean threads in manifold but I am worried about getting it into my oil.
 
The secret is to get the threaded holes and bolts completely oil free.
You can use a lot if Starter fluid without worry because it will dry completely without residue. You can always use a gun barrel bore brush if you want to really scrub the threads.
Silicone works for me.
 
Sounds good to me.
What type of silicone do you use that will hold up to engine temp?

They mostly ALL do, really, but if you concerned all that much go pick up a Permatex RTV Black toothpaste size tube off the wall at your parts house...

last I looked they wanted 5 bux for it....works like a charm good to over 600f last I heard.....


:crutches:
 
I have a 74 and I keep getting oil around the manifold bolts.
I have tried all kinds of sealants including permatext and teflon sealer.
Even tried replacing the bolts.
Was going to try tape but afraid it my get inside the engine.

Thanks in advance for any input.

4 speed

Here we go again,
The oil is starting to leak past my SS manifold bolts again.
I have tried every thing Permatex has to offer and still no luck.
For example, yesterday I went for a qucik ride and had no leaks.
This morning there was a puddle of oil next to a few manifold bolts.
This is in an unheated garage and I am wonderding if the SS bolts are contracting in the cold causing the leaks?
Thanks for input.
 
IS this showing around ALL of the intake bolts? Factory heads or aftermarket? Pulling them one at a time, spraying the threads with starting fluid or swabbing them out with alcohol to get all the oil out of the threads, then a coat of black RTV should work. THe only other option I can think of is putting copper washers under the bolt heads. And those aren't cheap. Off the top of my head, the injector copper washers for a Duramax diesel would be hard enough and about the right size- but they're like $7.00 each. I can look when I get home after the first of the year and see if I have some old ones laying around- no idea how many I can dig up.

Are you retorquing the intake after it gets hot and then cools off?
 
After many trys I finally stopped the oil from leaking pass the bolts.
My hunch was right, SS bolts and aluminum manifolds don't get along well.
I replaced the bolts with plain old black steel bolts and the leaking stopped.
Thanks for all the input.
 
Top