My 84 has leaked oil from the rear of the valve covers since I bought it about a year ago. After reading many threads on leaking valve covers, I purchased the fel-pro gaskets as were recommended by many. Much to my dismay after removing the driver side valve cover, I saw it already had a fel-pro gasket. After removing the valve cover and gasket, I saw that the there was no residual gasket on the engine and the valve cover was very clean.

I do not think my valve covers are the original, they are steel and polished on the outside with the 84 corvette symbol stamped on them. Closer inspection of the seating part of the valve cover revealed two circular indentations on each side of the bolt holes. These indentations span the width of the ribs of the fel-pro gasket so I think this is where the leak is coming from.

Does anyone have similar valve covers and what do you use to seal them? I have pictures if someone can tell me how to attach them to the post.
Thanks for reading,
Don

 

I had the same problem with valve covers. The lip of contact on the head is very small so any imperfections in that lip will cause a leak. I used a spray on sealer that is also tacky so the gaskets will stay in place while mounting made by Permatex. It's a good thing you tried the driver side first, the passenger side it a PITA.
Yes, you do have aftermarket from what it sounds like. Originals were cast looking with fins and a Corvette C4 logo. If you are concerned about sealing you could also try some RTV silastic sealant, I have used the suprer gray or black in just a thin layer on both sides.
I hope this helps.
Woody

 

If these are stamped steel, you may want to try using the rocker cover reinforcements and longer bolts, (the thickness of the reinforcements plus normal length bolts).
I have had good luck with these. They are basically a 4 inch long stamped piece of steel that fits the valve cover where the bolt goes, and tends to lengthen the grip area of the bolt. As you know, the 4 bolt arrangement is pretty weak.
Chevy cast the heads with sand, and the sand impressions were supposed to grip the gasket, and keep it from sliding away over time. The end result is thousands of places that oil can leak from when it gets hot and thin.
If you can't find any of these reinforcements, I may be able to come up with some for like $10 and I think I have some that are chrome. I know I have the original painted steel ones as well. Anyway, they help hold the gasket longer.
Prior to installing gaskets on stamped steel covers, you need to get a hammer, and hammer the gasket area flat like the rest of the gasket rail. It doesn't have to be perfect, just uniform.

The best way to secure the gasket that I have found, is to buy a product at your favorite auto parts store called "the right stuff". This is an advanced sealant that is pretty close to what GM uses on the engine assembly line. You put enough on the gasket rail to adhere the gasket to the cover, and place the cover gasket down on a firm, flat surface, and take a towel, and cover the rocker cover, and place a medium sized brick or other heavy flat object on the towel for maybe a half hour.. This will ensure that the sealant sets up on the cover, and won't move when you try to install it.
Do not over tighten the bolts as all that will do is warp the cover.
If you still can't get the cover to stop leaking, your best choice is to replace them with cast aluminum rocker covers. They tend to be more rigid and hold the gasket longer. The best place to find the is places like Summit racing .com, or Jegs.com. Usually they have lots to choose from, and they have good prices.

 

My 86 came with cast aluminum covers and no gasket just sealer from the factory.I agree with the other poster you need The Right Stuff gasket sealer and the felpro silicon rubber gaskets.You need to put the sealer on both sides of the gasket and then put covers on and tighten them down.The felpro's should have built in limiters and a steel core so you can't over tighten them.One other thing that makes the job much easier is to use threaded studs and nuts instead of bolts.The studs hold the gasket in place while you put the valve covers on.With metal covers as the previous poster said use the 4" metal hold downs to spread the load of the nuts.

 

Jim. Filling that divot with epoxy would be fine. People fill the too-large areas in intake ports with JB or equiv all the time. If your chip falls out, it will land on the exhaust manifold and stink a little. No biggie.

 

I think after 9 years, Jim has probably figured it out and is on to a different car by now.

 

On my old 84 I used a set of Moroso silicone valve cover gaskets. They did require longer bolts but sealed against the head flawlessly with zero leaks afterwards. They were blue in color and I apologize that I do not have a part number. I would not hesitate to use them again.

 

1. like you, I am having the same problem with my valve covers leaking. I tried the same ones that you are using. They aren’t much better than a cork , my valve covers may be leaking because I may have over tighten them time for some new gaskets and my valve cover just like yours. I bought the car brand new in 84 runs like a charm if you come up with anything good on how to stop the valve covers from leaking. Please let me know and my name is Kenny.