Oil Leak Through VC Studs
 

Hi all.

I have an Fe with aluminum heads and cast aluminum valve covers, with a leak on the right side. I replaced the valve cover gasket and it still leaks. Close inspection reveals the the leak is through the stud threads.

I removed the studs and wrapped them with teflon tape. Still leaks. Anyone know what I should use to seal the threads with?

Thanks in advance.

I'm guessing the oil is wicking in at the valve cover to gasket and spiraling up the stud.

Stat-o-seals work great for bolt leaks but I'm afraid they won't work on the studs (need a smooth shank area to seal).
https://www.parker.com/literature/Se...CSS%205125.pdf

Parker does make a Thread seal version that MSC stocks. https://www.mscdirect.com
https://www.mscdirect.com/product/details/65075848

Thanks. The gasket is tight and dry on both sides all the way around the studs. The holes the studs are in, at least the leaking ones, are not blind holes. The oil is coming into the bottom of the hole and going up the threads. The heads are aluminum so the studs get looser when the engine heats up.

I thought the teflon tape would do the trick, but maybe I didn’t wrap the studs enough times. Something that will seal the threads in the hole will do the trick, but I’m not sure what to use.

What about a thin Teflon washer with an interference fit to the stud? A channel dremeled from the stud to the valve side of the gasket surface to relieve the oil pressure at the threads? Maybe it's just simply bolts?

In all the years I've been doing this, I can say I have never ran into that one before.

Which valve cover holes? The ones in the intake or the ones in the heads?

It is the two lower holes in the head next to the exhaust ports. Only see this on the passenger side, driver side is not leaking.

Those holes in the head should be blind.

The thing is, even if they weren't, they don't hit oil. The only oil that's present is the level of oil draining back and then of course the pressure feed to the rockers. The pressure feed to the rockers is on the upper side of the head near the upper head studs.

Ive been having the same issue on a 289 with APR studs and fast valve covers.
I've been cutting 1/16" slices of 1/4" fuel hose with cutting pliers, and putting it between the nut flange and valve cover. Seems to work, but do still have one seeping.

Update on this. I pulled the valve cover again and determined it is leaking between the gasket and head rail. I reinstalled and tightened the lower 2 nuts in thenhead rail tighter than the upper 3 in the intake manifold. This slowed the leak down but did not completely eliminate it. I’m pondering my next move.

Everybody has their own solution for valve cover leaks and guys like Brent are the real experts. I recently fought this on my FE and here is what I did to solve it:

- Pull the cover and clean off ALL the old gasket material on the head, intake and on the valve cover. Check the finish on the sealing surface of the head and intake very carefully esp around the stud holes and use a stone to remove any burrs.
- Wait until your wife/significant other leaves and then place the valve cover on your kitchen surface plate (ie granite or quartz counter top). Make sure the cover is not warped and the seal flange is making good contact all the way around. If it is warped you can try to straighten it but hard to move the cast ones much
- Glue the new gasket to the valve cover using a THIN coat of permatex gasket SEALANT (not gasket MAKER).
- Put a bit of sealant on the head and intake sealing surface where the head and intake come together. On my engine there was a small step there and I could not get the covers to seal until I did that. You might want to put a bit around the studs too. If you don’t have solid lifters you can glue both sides of the gasket but it would be a real pain to clean it off if you ever need too. By the way Krud Kutter works great for removing the old sealant.
- Wait about 20 mins and put the cover on. By then the sealant will be tacky and the gaskets are less likely to move around
- torque down in star pattern. I actually torqued mine to maybe 8-10 ft lbs (ie pretty tight)
- wait 24 hours before starting

Hope it works.