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-   -   Oil leak around exhaust manifolds (https://67-72chevytrucks.com/vboard/showthread.php?t=622896)

Moose88 03-29-2014 07:04 PM

Oil leak around exhaust manifolds
 
For a while now I have had oil leaking onto my exhaust manifolds and I cannot figure out why. I had a mechanic "fix" it twice and it still leaks. After the first time he recommended that I replace the VCs because the old ones might be bent so I got new ones. He also replaced the PCV valve. But it still leaked. I then discovered that the VC bolts were hand loose :m6: and I decided to replace the gaskets that were glued on and the bolts. But it still leaks. On the driver side it looks as if the oil is "bubbling" up from the exhaust manifold connection to the block but i cannot tell if the oil is just running into the joint or originating from there. I cannot see where it is coming from on the passenger side.

Does anybody have any suggestions that I could try before I haul it in to a different mechanic? Thanks for your help!

Tx Firefighter 03-29-2014 07:51 PM

Re: Oil leak around exhaust manifolds
 
I'm a gasket snob I guess, but the days of cheap gaskets and silicone are in my past. FelPro makes a full line of Perma-Dry Plus gaskets that you install dry, no sealer, and they don't leak. Yes, they cost more. But they're reuseable and do not leak.

They're steel core with rubber faces.

http://i276.photobucket.com/albums/k...psd482c7b2.jpg

Use studs and spreader plates.

http://i276.photobucket.com/albums/k...psb3506149.jpg

And your leaking valve cover gaskets are nothing but a memory.

http://i276.photobucket.com/albums/k...psddd5793e.jpg

Then, remove your intake manifold bolts, one at a time. Clean it, put sealer on the threads and replace it. Then, repeat for the rest of them.

Now your intake bolts will stay clean and dry.

This is all the very most basic of mechanical projects, and fully doable by any truck owner. No sense in taking it to a mechanic for this type of thing.

Moose88 03-30-2014 12:26 PM

Re: Oil leak around exhaust manifolds
 
Thanks TX. I did replace the the gaskets with rubber/steel ones from Summit and I installed them dry. I also replaced the bolts with studs. I'll try cleaning and sealing all the bolts on the intake today. I'm afraid the leak is coming from blow-by because of a ring problem.

Tx Firefighter 03-30-2014 01:22 PM

Re: Oil leak around exhaust manifolds
 
Do you have oil coming out your tailpipe(s) ? You'd have soot accumulating back there if the blowby was that bad. Usually by that stage, you can run your finger inside of the tailpipe and get a wet, slimy, sticky finger back.

geezer#99 03-30-2014 02:58 PM

Re: Oil leak around exhaust manifolds
 
Two things to consider.
Do you have cork or rubber end seals on the intake or a bead of silicone?
Do you have a breather on the other valve cover?

twouvakind 03-30-2014 07:17 PM

Re: Oil leak around exhaust manifolds
 
like

Quote:

Originally Posted by tx firefighter (Post 6601828)
i'm a gasket snob i guess, but the days of cheap gaskets and silicone are in my past. Felpro makes a full line of perma-dry plus gaskets that you install dry, no sealer, and they don't leak. Yes, they cost more. But they're reuseable and do not leak.

They're steel core with rubber faces.

http://i276.photobucket.com/albums/k...psd482c7b2.jpg

use studs and spreader plates.

http://i276.photobucket.com/albums/k...psb3506149.jpg

and your leaking valve cover gaskets are nothing but a memory.

http://i276.photobucket.com/albums/k...psddd5793e.jpg

then, remove your intake manifold bolts, one at a time. Clean it, put sealer on the threads and replace it. Then, repeat for the rest of them.

Now your intake bolts will stay clean and dry.

This is all the very most basic of mechanical projects, and fully doable by any truck owner. No sense in taking it to a mechanic for this type of thing.



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