Valve Cover leak

[David Van Weele]

I think I finally solved a persistent oil leak that I have had for the last 10 years. That is how long it has been since I last had the cover on the passenger side off. Until this year I drove the car very little, on and off a trailer etc. I now drive my car about 20 miles a week and it seems to make everything run and sound better. But I find that I had a bad oil leak on to the exhaust manifold. I kept tightening the bolts holding the cover down until I felt I had gone far enough. I pulled the cover off tonight and found that I missed the top back hole in the gasket with the bolt when I last installed it. It is impossible to see until the cover is removed. I still had some of my 25 year old cork gaskets so I carefully made sure the bolts went through the holes before tightening them down. I will know tomorrow if I got it right this time. The moral to the story is be very careful when installing or replacing the valve covers, specially on an FI car where it is nearly impossible to see what you are doing.


MY 1963 Z06

[Bill W.]

Re: Valve Cover leak

Mornin' David,

Don't feel bad about missing your valve cover leak, I once pulled the motor from my freshly restored '65 fuel car because the rear main was leaking. Main seal was perfect. My right side valve cover was warped slightly and leaking down the rear of the motor. Clean oil on a freshly painted block is hard to spot. Bill

[Tom H.]

Use sewing thread

Place the gasket on the valve cover and use sewing thread through the holes to hold the gasket in place.

Place the cover and gasket on the engine and start all the bolts into their holes, but don't tighten them. After you're sure all the bolts are started in and everything is lined up properly, snip each thread and pull it out.

Now you can continue to tighten down the bolts and know that at least your gasket holes are in the right place.

Tom

[Joe L.]

Re: Valve Cover leak

David-----

If you use the steel core, Cork-Lam valve cover gaskets available from Fel-Pro, this condition cannot occur. Also, these gaskets will seal better than any other gasket which I have ever tried and I use them exclusively. Also, these gaskets have no "extra" set of holes for the 55-59 type heads.

The only "problem" with these gaskets is that they are a bit thicker than stock at about 5/16" thick. I "suffer" with this "transgression" in the interest of superior sealing. After all, that's what a gasket is supposed to do.

[David Van Weele]

Re: Use sewing thread

The only problem is that on a FI car the passenger side cover will not fit over the rocker arms if the gasket is on the cover. I tried using permetex to hold it on the cover but it does not fit even if you loosen the fuel line. Thanks for the suggestion.

[David Van Weele]

Re: Valve Cover leak

Joe .... I will try the lam gasket the next time I have to take the cover off. I ran the car today for about ten miles and thank heaven the leak is gone. When the car was new I must have had that cover off ten times in the first 10,000 miles since the valves would not stay in adjustment. So I guess I was just careless doing it the last time.

[Jeffrey S.]

Re: Valve Cover leak

David: I have been using the following technique for years on my 69 small block and have never had a leak or missed a bolt hole. I first use some ultra copper on the valve cover side of the gasket to adhere the gasket to the valve cover. I then put studs of the same thread size into the head where the bolts will go. I only run them in one turn or so so they are very loose. I then place the valve cover over the studs thereby guaranteeing that the valve cover is perfectly positioned. Then one by one I remove the studs and put in the bolt leaving the bolt a little loose. After all four of the studs have been removed and bolts run in, I tighten the bolts to the proper torque. Works every time. Try it and tell me what you think. Jeff

[David Van Weele]

Re: Valve Cover leak

Jeff.... Thanks for the suggestion. I used the black RTV to hold the gasket to the cover but when I tried to fit them between the fuel line and the rocker arms there is not enough clearance. The gasket must go on the head first. As far a using the studs that is a great idea if you have the clearance but with a Fuel Injected mid-year there is not enough room.