Any suggestions? I have a persistent oil leak from under my pressed steel valve cover using a cork gasket, is there a neoprene one that works better?

I've always used cork. If it isn't sealing try adding a washer under the cap nuts to get more compression of the gasket.

Traditionaly, rubber leaks worse on almost every aplication. I say almost, leaving room for one that might seal better with it that I might not know about. I've never seen one that rubber worked better on.


Rubber is mainly used when you plan to remove the cover often, like on a race car. This is why you'll see them listed as "high performance" gaskets, even though they don't perform better.

Personally, I like Ultra Black instead of a gasket. It's really good stuff and is designed to swell when it comes in contact with oil. GM dumped v/c and pan gaskets on alot of models years ago and went strictly with a 1/4 bead of sealer. It's my prefered method as well, whatever that's worth.

Ultra Blue is good too, but looks tacky IMO.


Nothing says "hack job" quite like finger smeared blue silicone drooling down the side of an engine. Anytime I see blue silicone I get that image.

Only thing worse is blue silicone fingerprints on the fender well.

I use cork and have no leaks. I spray it with High Tack on the valve cover side, mainly to keep it in position when putting the cover back on. Maybe your valve cover is bent slightly.

I used they grey coloured sealant (think it's the OE Ford type stuff) on a cork gasket, I used the sealant on both sides (which I don't think you are supposed to do because it might not break free very easy), but at any rate when I took the cover off to adjust the valves the gasket stayed on the rocker cover & didn't tear, I have had it off & on 3 more time since then & no leaks, nice smooth rubbery surface from the sealant on the cork gasket & seems to seal up just fine.

I've seen silicone gaskets available for valve covers and tappet covers. They sound like a good idea. Any experience with them?

Payen cork, Payen always, always fit better than the cheaper stuff.

I tried one of those silicone VC gaskets and got almost 2 blocks from home before it blew oil all over the engine bay and street. Back to cork for me.

Alot of folks use gasket sealer on gaskets. I did too for hundreds of years, until I learned "the truth". There are two distinct camps on this thought.

If you ever tear down a factory assembled componant, you'll notice there is no sealer on factory gaskets (this excluding some of the newer gaskets having a sealer bead "printed" around ports. Some new Felpro gaskets come with this.)

(Some folks say gasket sealer isn't needed anymore than a water pump needs the water pump "lubricate" sold on the chemical isle in most stores.
" The thought is, "How can you lubricate a sealed unit???" Now I know.....some folks say it lubricates the pump seals...which antifreeze is supposed to do anyway. I don't wish to start a debate on this or anything else. Personally, I don't care if someone uses it or not, it certainly can't hurt TTBOMK.)

They state the gasket does all of the sealing, thus sealer is not required.

Other folks say it is mandatory. (Especially the people who make the stuff.)
They state it fills in imperfections in the mating surfaces allowing a better seal.

If a surface can be sealed from the factory with just a gasket, then it should be able to be sealed at home in the same way......unless some yahoo gouged the crap out of the surface while preping it.

Cork is "always" supposed to go on dry, with small amounts of "sealer" used in an adhesive role to keep the gasket in place durring assembly. (and in corners too where two gaskets or a seal meets.)

Do ~I~ use sealer on a gasket????

Sometimes, depending on surface conditions, application and intended usage.

I try to get away with using it as little as possible, but I do use it.



Here's a basic guide, some may have other opinions on this:

"Dry" gaskets can be used either way, although I don't use sealant unless surface is screwwed up.

Silicone is a gasket replacement, not a sealer.

Head gaskets shouldn't be used with sealant. ( although I am really tempted to use copper coat on them as I really like the stuff, which I do sometimes use, depending on surface and gasket material.)

Some head gaskets use a graffite coating and it is believed by some to allow the head and gasket to expand and contract with temp (same w/ exhast gskts).

When you use sealant, you restrict this movment which may lead to the gasket failing due to gasket stretch and tear. These are the ones that I'm tempted the most to soak down with copper coat, even though I know I probably shouldn't. Old habbits are hard to break. I can see both sides of the arguement, it just depends on what mood I'm in at the moment.

Here's something you can take to the bank: If a gasket comes with sealer printed around ports (or rubber "seals"), DO NOT USE ANY OTHER TYPE OF SEALANT ON IT UNLESS INCLUDED AND INSTRUCTIONS SPECIFICALLY STATES SO!!!!

It already has sealant, no need for more as it'll usually make it leak. They've gone to the trouble for you already, just leave it alone and put it on. You can use a dab to hold it in place, but NOT on the printed sealer or rubber.

The older type of cheap blue silicone used on a "dry" gasket will usually make this happen as well, especially cork . What happens is as cork drys, becomes more brittle and shrinks as it ages while silicone says flexible and the same size.

As the cork gasket gets smaller, it pulls away from the silicone sometimes leaving gaps or tearing the gasket if it's stuck to the other side by the sealer and not allowed to shrink freely.

Here's another "take to the bank": NEVER, EVER, EVER, EVER, use silicone type sealers on surfaces that are clearance dependent, like case halves of a VW or outboard engine or other two stroke.

Silicone doesn't "smush" all the way out and leaves a film .001-.005 thick.

It doesn't sound like big deal, until you consider that main bearing crush is directly dependent on the distance b/w case halves. That extra .001-.005 just turned into and extra .001-.005 of main bearing clearance AND, the bearing is more likely to spin in it's bore as it's now not held in tightly.

( two strokes use caged roller or ball bearings, but the same applies but for slighly different reasons.)

Aviation Permatex or "300" IIRC is perfect for such areas.

Honda and Yamaha have a grey sealer for those areas as well, but with different properties than the stuff you are using.

Bottom line, it's all a personal belief system and prefference.

Kinda like ketchup on eggs, or steak sause on steak.
(Can't STAND either abomination !!!)


Some say gasket sealer is a gimmick; others a God send.


I believe it can be both.

Rest assured, I may have left something out......and others may (will) disagree.

The grey stuff you have is good stuff too.

I've always just used cork. I coat it with oil before putting it on, NO SEALANT. No leaks either. I used 'em twice, then replace just on principle. I never torque the cover on, just until it feel snug, and it doesn't leak.

YMMV

Aviation sealer on the valve cover and cork gasket mating surface, nothing between the head and the gasket and it seems to do the trick. I hate working with the aviation sealer but it really seems to work best for me on valve cover and themostat housings.

Kellysguy, that's the most heart felt reply on gaskets and sealants I've ever seen. I'd like to pick a couple of points you mentioned and apply them to what's been said by others.

When our cars were new and hadn't been molested by previous owners, the valve cover and the cylinder head top surface were both flat and no gasket sealant should have been needed. Now that our cars are older and the valve covers have been abused and distorted by years of previous owners over-torquing the valve cover bolts/nuts, that sealing surface isn't necessarily flat anymore. This creates gaps, gaps where gasket sealant can help.

For the past 15+ years I have used the following method for valve cover gaskets. The method has always given me nice, well sealed valve covers that are easily removed. I remove all traces of the old gasket from the head and valve cover. I degrease the valve cover where the seal goes. I use a thin bead of RTV on the valve cover where the gasket goes, put the gasket on the head (dry) and place the valve cover down on the gasket. I tighten the valve cover nuts "finger tight" and leave things to cure over night. The next day I remove the valve cover and wipe the bottom surface of the gasket with a thin film of oil and fit the valve cover and tighten the securing nuts properly.

As you mentioned, there can be gaps. The RTV fills those gaps to the warped component and it leaves the bottom surface (to the head) clean and flat. If you don't like RTV, there are other sealants to consider. I know people who use 3M trim cement and I know people who use Permatex. At that point it's whatever you like.

I use cork gaskets. I don't have a good reason, I just like them. FWIW, if you are using the silicone gaskets, using my method above with RTV to seal the gasket to the cover should work very well. The RTV will adhere very well to the silicone gaskets.

3M 8001 does work really well, but MAN is it a pain to remove. I quit using it for that reason. I've been tempted to see just how far 3M 5200 can be pushed, but I'm too lazy to redo anthing if it fails. I don't know what all a marine sealant will take if it's subjected to a totally different environment. I'm sure it can't do any worse than a trim adhesive in the same realm, but who knows.

One thing about both of them, you better make sure that where ever you put it is where you want it to be, cause it aint movin' once it drys.

5200 is some tought stuff, more so than 8001 and I hate cleaning that up. If only 5200 came in black.

One thing's for sure, 3M makes some great products.

I usually go with Permetex 2B for thermostat housings and as a gasket adhesive.

Like you said, "it's whatever you like."

2B.......or not 2B.......THAT is the question......

How do you feel about ketchup on eggs and the use of steak sauce?

3M trim adhesive between valve cover and gasket. Gun grease between gasket and head. Gasket stands up to many removal's. I'm with Hap, Payen gasket seems the best. I have a pile of substandard ones on hand to keep for emergency. Keep them stretched over an old valve cover so they don't shrink.
KA.

It's another case of "it's whatever you like". But... I prefer Tabasco to ketchup and I never use steak sauce on eggs.

+1 for Tabasco on eggs (and anything else) !!!!

I didn't mean steak sauce on eggs; rather on steak.

I do a MEAN eggs over easy deep fried in bacon grease w/ Tony Chachere's, garlic and onion powders then drizzle some Tabasco on them after they come out.

Sure,......it'll kill ya, but MAN do they taste good that way.

Pressed garlic on them while they're cookin' is better, but we don't always have freh garlic on hand. I'm not a big fan of "powedered" anything, unless it's sprayed on car parts. This excluded powedered sugar.

I haven't eaten breakfats yet, can you tell???

Might go fix me some eggs and bacon !!!!


Nomad, that's a great idea storing them over a v/c !

Mom had a BIG dictionary from college that was about six or seven inches thick. Dad use to store gaskets in and under it. I always found it funny that was the only time he ever used it. If you ever saw his spelling, you'd understand. he'd get mad at me if I didn't put his gaskets back in it, like that's what it's meant for.

I've used cork valve cover gaskets on the VW for years and never had them leak. In fact, cork may be the only thing available. Anyway, I always use non-hardening permatex or other similar sealer between gasket and cover just to hold it in place with nothing between gasket and head except maybe a little oil. That way the gaskets can be used several times (a necessary "feature" of the Bug) before replacing them.

Thanks for that info. I was thinking about using these and glad I asked here first.

If the cork gasket gets oily, how do you get it to stick to the adhesive? I tried to clean mine with acetone, but it still didn't bond very well.

I wonder if my valve cover has a problem: the gasket wants to keep squeezing into the cover above the forward exhaust port. The valve cover is the original one off the donor car and has had the filler modified to fit under my hood (the Westfield is very low in front), so I would like to try and make it work. It is, I assume, a stock 1967 pressed steel valve cover. How much of an inner lip should there be to keep the seal in place? If I tighten down on the cover enough to stop the oil from weeping into the spark plugs it squeezes the seal into the cover and it leaks onto the front exhaust pipe.

FWIW, I am almost certain that the cast alloy type are too tall for me to use under the Westy hood, I had to shorten the filler as much as possible to get this one to fit. There may also be an issue of inner clearance with the roller rockers too.