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Hello Gentlemen, I have a 1986 Chev pickup truck with a 350 engine and Edelbrock heads. I can't seem to stop an oil leak from my valve cover on the passenger side. I replaced the gaskets three times with cork, Fel Pro, and Silicone. Each time I replaced them the oil leak would stop but gradually return until I could smell it burning. The oil leak seems to be at the back of the engine. It runs down the block after I park it overnight. The valve covers I had on it were from Edelbrock. I have since changed them after the last leak with a set of chrome valve covers with an even thicker cork gasket. It has now begun to leak again. Valve cover bolts still tight. Any suggestions?
 

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Hello Gentlemen, I have a 1986 Chev pickup truck with a 350 engine and Edelbrock heads. I can't seem to stop an oil leak from my valve cover on the passenger side. I replaced the gaskets three times with cork, Fel Pro, and Silicone. Each time I replaced them the oil leak would stop but gradually return until I could smell it burning. The oil leak seems to be at the back of the engine. It runs down the block after I park it overnight. The valve covers I had on it were from Edelbrock. I have since changed them after the last leak with a set of chrome valve covers with an even thicker cork gasket. It has now begun to leak again. Valve cover bolts still tight. Any suggestions?
My suggestion is grab a mirror and a flashlight and look closely, I suspect your leak is at the china wall. Not hard to fix. Pull the intake, get rid of whatever gasket/rtv that on the rails, run a bead of permatex black with a overlap bead on the ends and button it back up.
 

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Were both sets of covers stamped steel??

If so, were you using the 3" long load spreaders at each location?? These help a lot.

You can find decent polished cast aluminum covers all over Ebay for around $45, they are a lot more rigid and seal up much better.

It could easily be what Bygddy has posted also about the rear intake end seal rail
 

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Thanks for your advice, I don't think that explains the fact that the leak stops after I change the gaskets and gradually returns, wouldn't I have a vacuum problem if the china wall wasn't properly sealed?
 

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Thanks I have load spreaders and the covers a stamped.
Stamped can be a PITA even with load spreaders, I was just looking for the easy things first.

Get some Cast aluminum covers and you'll never want to see a stamped set again. :thumbup:
 

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My suggestion is grab a mirror and a flashlight and look closely, I suspect your leak is at the china wall. Not hard to fix. Pull the intake, get rid of whatever gasket/rtv that on the rails, run a bead of permatex black with a overlap bead on the ends and button it back up.
I agree....
 

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Your earlier post (#6) says they are stamped, If I read it and the first post correctly.

Edelbrock makes both a stamped steel chrome plated cover and a Diecast aluminum cover.

Are you glueing the gasket with any kind of sealer??
 

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Thanks for your advice, I don't think that explains the fact that the leak stops after I change the gaskets and gradually returns, wouldn't I have a vacuum problem if the china wall wasn't properly sealed?
No vacuum problem, that area doesn't get into the intake ports, just into the lifter valley/crankcase.

Sometimes you can clean everything up when you change valvecover gaskets, and in the process of cleaning you've cleaned the block/ intake area also, so a leak here takes a little time to show up again as a drip/mess...and the valvecover gasket isn't leaking at all. Trips up folks alot.

Clean the area good, drive a little and get in there and look close, mirror or whatever. You might have to drive a few minutes..or days. or a week...whatever amount of time is making your leak come back right now -try to look at the area at 1/2 that amount of use...to chase the leak down.
 

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Thanks that kind of sucks I just had the mixer off last week the truck runs on propane just finished rebuilding it. I live in Canada I don't know where your from still to cold to work on the truck froze my but off last week getting the mixer on and off.
 

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Thanks that kind of sucks I just had the mixer off last week the truck runs on propane just finished rebuilding it. I live in Canada I don't know where your from still to cold to work on the truck froze my but off last week getting the mixer on and off.
I feel your pain.... we got 10cm a few days ago and no heat in the garage means I'm still a couple weeks away from touching a damn thing lol.
 

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Checkout these valve covers: White Performance Detail Description They look pretty good and with a heavy duty rail. Not bad a deal for the money. I use a sealant called Permatex® Indian Head® Gasket Shellac Compound. I apply to valve cover using cork gaskets and let dry. Then apply to clean rails and the gasket and let dry until tacky. Install the valve covers and snug bolts with 1/4" drive socket set. You will have to use a rubber mallet to remove the valve covers.
 

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I think everyone has given very good recommendations (and, probably the correct solutions), but I'lll go out on a Limb here and give you mine (which is, admittedly, a little out there and probably not the problem, however it is something to ponder)-

I have a friend who is a very good engine Builder, and he has told me of having these types of problems due to poor Oil drain back (the returns in the Heads are either not big enough, or not even there!)-this problem is especially acute on some AFR Heads (and, some Edelbrock's), so, his solution is to put them in his Mill and cut more returns in the Head-the symptoms go from leaky Valve Cover Gaskets to leaky Head Gaskets-

He is a respected Builder, and has told both AFR and Edelbrock about his modification-
 
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