Valve Cover leaking

[Capt Kirk]

Well first a little background:

Last week I replaced my front seal (did a little every day, made it more enjoyable) while out there wrenching my mm came out and complained about how dirty my engine was in general. Telling her that I was tracking down leaks and that I'll clean it when I'm done got her off my back until today. I finally desided that I should take it down to the coin-op car wash and spray it down (BIG help, I didn't know my Vacuum pump was silver until today).

I also replaced the Valve Cover gasket thinking that the old one was leaking. But now it is leaking a lot out of the very front right of the gasket about that bolt for the timing chain doohickie. I sprayed the area down with Brake cleaner so it was clean and dry, drove it around for a few minutes and when I popped the hood there was more oil slowly puddling in that area.


So basically my question is can I help that area with some gasket sealant under the valve cover /gasket, or even on the outside just kind of build it up and hope it holds?

Also there seems to be a little rubber gromet to keep you from cranking down too much on the cover (it's on the front right bolt) could I remove that to get a little extra hold?

I would say your gasket slipped. I use some gasket glue to seal mine to the cover.
I have never had to remove tabs to get it to seal.
Don't over tighten the four nut's. And I do it in a star pattern. Or X pattern if you will. Plus I clean the heck out it while it is off{valve cover}.
Good luck.
Charlie

[Capt Kirk]

I put a nice line of gasket sealant in the problem area with the back of a #2 pencil (I was going for the professional look )

seems to have helped a lot. When I go in for the next Valve Adjustment I'll do a proper job of sealing that area, but for now the oil doesn't puddle in the area after a few minutes.

I agree with Charlie. The way these gaskets fit, if they are installed correctly, they just won't leak, especially a new gasket. There is absolutely no need for sealer on one of these gaskets.

Good luck,

[JimSmith]

Capt. Kirk,

This is one of those procedures I learned the hard way. I now always do an engine wash before I take the valve cover off, as once it is off there is nothing to prevent you from scattering greasy road grit into the exposed mechanical stuff. And it is that much harder to ensure when you put things back together there is none of that black, greasy grit under the gasket. The first time I did this I was aghast at the prospect of having the stuff fall in or get scraped into the gasket seating area, so I spent about two hours and two rolls of paper towels wiping the area down being careful to push the crud out and away from the guts. Power washing the area before the job is much cleaner and faster.

I do not use a gasket sealer, but I do use a high temperature synthetic grease compound (Redline makes one and you can find them at NAPA or any other auto parts store) to seat the gasket on the cover and the gasket on the cylinder head. A thin coating on each CLEAN surface prevents damaging the gasket when you slide the cover around to align bolt holes, and provides a filler that has to be pushed out of any defects before oil can leak out. These gaskets do not see oil pressure behind them so an assembly grease will work well to keep the joint dry.

Any dirt under the gasket and you will be sure to have a leak. The same with any sharp nicks, dings and raised metal on the cylinder head gasket seating surface. These have to be removed and smoothed into the adjacent surfaces or the joint has a built in drain line to the outside of the engine. In your case I would look carefully at the metal and the gasket in the area of the leak to find evidence of why you have the leak. Also inspect the fastener in that area - try running the nut down the stud by hand with the cover off, looking out for roughness or galling. Any evidence of difficulty turning the nut is an opportunity for the joint to be assembled with uneven closing force at each fastener, which is also a formula for causing a leak.

Be careful not to overtighten the cover fasteners, as I did on my 300E recently, and broke one. On the Diesel models this is a little more of a problem as the male part of the fastening hardware is a stud sticking out of the head. This configuration can also contribute to damaging the threads removing and installing the cover.

Good luck and I hope this helps. Jim

A local MB tech showed me that the valve covers on these old machines can warp on occasion. Take the valve cover and sit it on a piece of flat glass. You can see where it lifts.
Then take a flat sander and work the high spots down. Keep at it and it will quickly become flat again. Then inspect to make sure you round off the sharp ridges, they will cut up you gasket.
I like Jim Smith method of sealing. Most of these valve covers will be a little warped though, and could use some help.

[Capt Kirk]

thx guys for the help. My little patch seems to hold for now, but next time the cover is off I'll try what you're talking about Jim. I never really liked the idea of using gasket sealant but in some instances it's useful, your idea lets me get around using it.

[waybomb]

I did my gasket a while back and simply tightened it down going in a sort of criss-cross-patern until snug. Leaked bad out the front.
Hmm
So I took it apart, did the straight edge, it was flat. Inspected the gasket and both mating surfaces. Nothing wrong.
I then pulled the studs. One of them had a much thinner shoulder on the stud. So, I reinstalled the studs, slipped the cover back on, and was very careful of tightening the three similar studs in a criss-cross-pattern until snug, then snugged up the odd-ball.
Worked great and no leaks. Someone must have broke a stud or replaced it with an oddball for some reason.
Fred