Cam Cover leak

Steve Meltzer · Post by **Steve Meltzer** » Thu Nov 30, 2006 11:45 pm

I just replaced the left cam cover on my 330 GTC, having done so because of a small oil leak onto the first two plug wires. While replacing the gasket I noticed that the little semi-circular "O-ring", at the front of the cam/engine was torn. I didn't have another, so I glued the broken area, and siliconed it back into its groove. I took my time and cleaned all of the surfaces very well, but it's no better than it was. In fact, it's the same leak, in the same place. Is this a common leak on these V-12s? Any thoughts? For $50, that new gasket was pretty pathetic. Sure made me pine away for the hefty gaskets on my old Chevy SBs. thanx steve meltzer..."I may be wrong, but I'm never in doubt"

Post by **330GT** » Fri Dec 01, 2006 10:35 am

Actually, that O-ring isn't semi-circular, but a complete circle. The rest of it is between the head and timing chest, impossible to replace in one piece unless you take a lot more apart.

This is a notorious spot for leaking as it is a four way joint between the head, timing chest, chain and valve covers. The O-ring is easy to damage as it fits into a groove in the chain cover and you have to use some thin shim stock to allow the valve cover to slide down beside it.

I haven't tried this, but the rubber people say that instant glue (Cyanoacrylate) is the best for bonding two pieces of rubber together. That's what they use now at the corners of windshield rubber. Anyway, one of mine is torn, so the next time I check the valve adjustment, I'm going to trim both ends flat and glue a new top half on. That and some judicious use of silicone rubber should fix my leak.

Here's what the FAF Tuning Tips and Maintenance Techniques book says:

Remove the chain covers and lift the old gasket off. Avoid damaging the front circular seal and be careful not to drop any pieces of gasket into the engine. Clean the area under the gasket and remove all adhesives. Install the new gasket, carefully cutting off the small section of gasket over the distributor drive. The circular seal between the cylinder head and the chain cover should be carefully inserted through the small punched squares in the gasket. Push the gasket down on the cylinder head. Do not use adhesives to hold the gasket.

I think that I left the O-rings in one piece so I must have cut the punched squares. From these instructions, I guess that you should cut the O-ring at the top so it can fit through the square holes? If so, won't it be difficult to keep in in the chain cover groove while installing the valve cover? It's been several years since I did this. Hopefully someone with recent experience (TomY/JimmyR?) can help out.

Steve Meltzer · Post by **Steve Meltzer** » Fri Dec 01, 2006 12:52 pm

Kerry, thanx for your detailed note. My friend, who was helping on this little project, also suggested the use of the cyanoacrylate (which we did) and we used a thin shim to wedge the little bugger into its groove in the cover. However, the gasket I got from T. Rutlands was really thin...very different from the one I was replacing; we glued it to the head using "Permatex High Tack", then I put silcone ("Agent" Orange) on the top surface of the gasket, all over that big O-ing and its groove and the cam housing "humps" between the head the timing chain and head and distibutor. Let it dry 24 hrs and, "viola", it leaked again. Argghh!

Do you think I should try a little silicone on the lower lip/seam between the cover and the head over those two plugs or ??

thanx again. steve

Jimmyr · Post by **Jimmyr** » Fri Dec 01, 2006 4:40 pm

If you get sealant on the face of the "O" ring the shim could grab on and pull it up. The O ring should be smooth and lightly oiled ditto with the shim; do not use grease as it again could pull on the O ring. Also, it is best to cut the O ring at the top and slip the gasket over it and not cut the gasket. Careful using too much sealant, if it squishes into the engne and the oil gets at it some of it could become lodged elsewhere like the oil pump screen or worse.
There is a proceedure in torquing the cam cover down that could prevent leaks. First set the chain cover down, but not tightened, then the cam cover using the shim. Then start all of the nuts and distributor bolts, but do not tighten. Then run the cam cover nuts down using a circle pattern much like the head gasket tightning pattern. Then tighten the distributor nuts and bolts secure. Remove the shim and tighten the chain cover down. Depending on your engine type secure whatever attaches to the front of the chain cover (oil filler, breather, etc. Note, a shim and oil could be helpful by the distributor O ring if you dod not loosen it enough to be sure it is not damaged. Jim

Steve Meltzer · Post by **Steve Meltzer** » Fri Dec 01, 2006 8:20 pm

Jim, thanx for the info. I'll have to see if I want to redo this. Do you recommend the thin gasket I got from T. Rutlands? Do you use any sort of sealant on it? If so, where? thanx steve

Stephanm · Post by **Stephanm** » Fri Dec 01, 2006 9:09 pm

This is a difficult area but a little creativity with silicone can solve most problems.
You want to apply the silicone and set your covers without clamping anything down. Wait for 1 hour for the silicone to set up a little and then clamp the nuts down. The silicone will form a "skin" so it can stay in and compress and not just squeeze out.

Make sure to remove ALL (using chemical cleaner like brake cleaner) old silicone as nothing sticks to silicone, including---Silicone!!!

Jimmyr · Post by **Jimmyr** » Fri Dec 01, 2006 10:50 pm

Steve, GT Parts in Phoenix makes their own gaskets and they are MUCH thicker than the OEM paper ones and they compress nice. As for silicone, unless you have groved or scratched or warped surfaces the silicone or Permatex may hinder removal or squish into the oil system if you are not extreemly careful. I only use a dab of the good oil proof silicone material gray or red (read the lable for oil resistant) where the gasket is cut or ends. I.E. next to the cut at the distributor and front chain cover - that is all. Apply to the outside 50% of the surface only and install the cover when it is still wet, the small amount will then form into the space and not into the engine. Then wait a few hours until it sets before starting the engine. The non oil resistant silicones can soften in the presents of oil or gas and should be avoided. Many new cars use only form in place silicone gaskets today, but the surfaces are designed for this system. Take your time and think it thru as you do it, there is nothing magical about old Ferrari engines they were made by people who were very logical. Jim

Bryan P · Post by **Bryan P** » Sat Dec 02, 2006 11:19 am

I managed to tear both my o-rings when removing the cam covers for blasing and new paint. I "glued the o-rings back on w/ the "agent orange", but then I used the gore-tex tape solution instead of the typical cam cover gaskets that Michael B tunred me onto (from the Daytona site, I think?). the gore-tex was a PITA to put on - you'll use a lot of exacto blades - but my cam covers have been absolutely leak-free for 8 months now.

Steve Meltzer · Post by **Steve Meltzer** » Sat Dec 02, 2006 9:34 pm

if/when I pull the cam cover (burned out on this now!) i'll get the one from GT parts. have you ever used this sealant made by Permatex, called "The Right Stuff". It used in place of a gasket, supposed to be great stuff. Expensive, but way cheaper than even the gasket itself. thanx again. steve

Jimmyr · Post by **Jimmyr** » Sun Dec 03, 2006 6:08 pm

When installing a new cam cover gasket loosly lay the gasket on top of the studs without pushing it down. Observe any misalignment between the studs and the gasket holes. Some new gaskets may not exactly line up with your cars studs. This may be because of the way the gasket was made, or material shrinkage, or bent studs, etc. In any event looking down on the gasket use a heavy felt tip marker and mark any areas of the gasket that do not clear the studs. I then use a paper hole punch from the office supply store (about a dollar), and lift the gasket and take a small punch where the marker indicated a mismatch. The gasket should then fall easilly onto the studs without pressure. Note, unless the gasket if free to clear the studs the threaded ends of the studs will easilly tear the gasket. Jim

Rudy van Daalen Wetters · Sun Dec 03, 2006 6:29 pm

Good pointers, Jim. I am printing this thread out and keeping it handy for the next time. I don't want to have to learn the hard way on this procedure.

Rudy van Daalen Wetters
1963 GTE s/n 4001
1966 330 GT s/n 8705

Bryan P · Post by **Bryan P** » Sun Dec 03, 2006 9:24 pm

found it - http://www.daytonaregistry.com/originality/lgor.html
gore-tex "Expanded PTFE" tape. good stuff, expecially if someone in the past buggered your cam cover or head faces with a screwdriver trying to remove the covers . . .

Steve Meltzer · Post by **Steve Meltzer** » Sun Dec 03, 2006 10:23 pm

That is very, very interesting! Anyone ever use the gasket maker by Permatex called "The Right Stuff"? I was afraid to use it there (not sure why) but it's supposed to be awesome also. thanx again. steve

Steve Meltzer · Post by **Steve Meltzer** » Mon Jan 08, 2007 9:21 pm

It's been about 6 weeks since I posted this question. At that time, I cleaned up the seam between the cover and the head using some lacquer thinner and a wire brush. Then I applied a small amount of Permatex "The Right Stuff" in the seam. You can barely see it at all. It's been dry now for all of this time (yes, I have driven it about 200 miles or so). Better to be lucky than good! steve