stopping a leaking valve cover gasket?

[rrubel]

I'm facing what's hopefully my last problem - a leaking driver's side valve cover gasket. I have new heads (take both center and perimeter-bolt covers), almost-new covers (GM Performance), and almost-new FelPro blue gaskets. I also have a second set of new FelPros waiting to go on.

The problem is that I cannot get the bottom of the valve cover to stop weeping oil. It doesn't really happen much at idle, but when revving the engine I get enough oil to start dripping onto the headers and make a nice blue cloud.

My Haynes manual says the torque spec should be between 55 and 120 INCH-lbs; I set my torque wrench to 10 lb-ft, which should be 120 in-lbs, and still had the leak.

Last night I got desperate enough to even put a small bead of blue Permatex on the gasket. Didn't help. If I hold a mirror under the bottom of the cover, I can see just the edge of the gasket with a film of oil running along where the gasket meets the cover.

I realize that there should be no pressure under the covers... so whatever is flowing, is flowing because there's an easy path to follow and I cannot seem to find it.

Any suggestions would be welcome!
Thanks.
[RICHR]

 

[rrubel]

I just had a thought. Could the holes for the perimeter bolts on these heads be interfering with the proper seating of the centerbolt covers? Should I grind them down? I only need the centerbolt holes... the perimeter bolt holes aren't sticking up or anything, but might be keeping the shell of the cover from dropping down as far as it should.
[RICHR]

 

[unleadedbrew]

My Haynes manual says the torque spec should be between 55 and 120 INCH-lbs; I set my torque wrench to 10 lb-ft, which should be 120 in-lbs, and still had the leak.


Rich, I've got Corvette project book that says the torque for center-bolt style covers should be 90 inch-pounds.
Just a thought.

Gordon

 

[JonM]

You may also want to try Mr Gaskets, Ultra Seal' Ultra-20 material swells to a controlled thickness for a tight seal. It will not contract or need re-torquing. A black latex coating helps create a tight seal and assures easy removal. High tensile strength improves performance.




http://www.mrgasket.com/pdf/Gaskets.pdf

Mr Gasket

 

[Ken]

Rich, I first tried using the Earl's "Pressure Master" valve cover gaskets when I put my engine together. These gaskets are very expensive and normally seal quite well.

In my case however, the Edelbrock E-Tec heads I'm using are perimeter bolt only, as are my valve covers of course, but the heads themselves have bolt holes that are cut back to a half-circle so the gasket actually only contacts the outside portion of the head. I was leaking through and around those areas, so I simply switched back to cork gaskets and haven't had the problem since. Might try something like that if you cannot determine that the cover isn't bent or something. Maybe it's hung up somewhere and not fully seating.

You'll get it!

 

[taegdh]

I ditto Ken's reply.

But I wonder if you are having pressure building up inside the crank case. I'd give the PCV a shake and a shot with Gum Cutter or the equivalent to clean it out..... Also give the PCV hose a shot to make certain it isn't blocked. If it is you're not getting any vacuum in the crankcase, hence it isn't sucking the blow-by gasses out. Pressure is building up in there and the valve cover gasket is the weak link in the sealing.....

 

[rrubel]

The PCV shakes fine, and the hose connecting it is new (most of those hoses are). I'll take a vacuum gauge to it, though.

I do think it's related to the perimeter bolt holes and the center bolt covers. I did some measuring and found that the groove in the bottom of the cover is not wide enough to fit over the bolt holes (bosses?). So the cover would sit against them and not actually compress the gasket at all so oil would pass over it. Wonder, though, why the passenger side isn't leaking. Dumb luck, maybe.

I'm grinding down the perimeter bolt holes with a Dremel tool, being sure to cover the rest of the head with damp paper towels to pick up the aluminum filings. HOPEFULLY that'll do the trick.

Thanks for the suggestions. If this doesn't take care of it, I'll try some of the other gasket stuff.

[RICHR]