I replaced my leaking valve cover gaskets and "half moons" the other day. Ordered new paper gaskets from SNG Barrett along with a tube of hylomar.

A few comments:

Taking the old gaskets off was a huge ordeal. I'm almost certain they were original and virtually fused to the valve covers. In an effort to be meticulous and not mar the covers whatsoever, I spent what seemed like an eternity removing. Carb cleaner worked the best to loosen, but just barely. Brute force plain and simple. Permatex gasket remover, brake cleaner, goo gone, wd40 and pb blaster all seemed useless.

Coated the new gaskets with hylomar based on very positive reviews of that product.

Now to my question: I did have some of the hylomar squeeze out when torqing the bolts to spec via a torque wrench. I wiped it up, but how worried should I be about what may have squeezed inside??

This was the first time I did any gasket work and while I was proud of my handiwork, I'm now thinking I used too much Hylomar and screwed up.

Thanks Again,
Doug

 

In a word, NONE.

It will small, and the oil filter will pick it up anyway.

It is NOT a solid item, as in metal, carbon, etc, so will do no damage as such.

Some will worry about it blocking the oil pump screen, NAH, it is simply not enough quantity to do that. It will only be a string or 2 at best.

I dont use gaskets on that area anymore, just the "D" seals and Hi-Temp RTV, never had a leak yet. Do the same on the V12 engines also.

 

+1 to each point Grant listed, including the sole use of liquid gasket material only in this type of application. That which I use is a CRC product I think, branded "3". It is darn expensive but you use so little and it is so reliable.

All those cork sump, cam cover and t/c cover gasket sets, once hot and soaked in hot engine oil, leak like ole grandpa's water bucket - perhaps not at the seal areas, but straight through the porous cork. Replacing them with liquid gaskets is a smart move that will prevent leaks forever. Moreover, I see them being used in place of OEM gasket sets on transmissions, differentials - indeed anywhere you want a leak free solution in the presence of hot lubricating oil.

Cheers,

Ken

 

when using Hylomar, (which I don't believe it is designed for valve cover gasket applications, but for Fuel lines), use very little, only a thin layer is needed.

 

A safer option is to use a non-setting gasket sealant such as loctite 518 which dissolves in oil. Blue Hylomar is a non setting gasket which I normally favour for coolant pipes, but it should be fine for the cam covers, provided you don'e get too much into the engine.

 

Old tech:


1. Cement the gasket to the removable part, never the stationary. Applies here to cam covers.


New tech


2. As Grant says Hi temp RTV. I've used it on exhaust manifold to head joints. so far, just fine...Decade or so ago...


Carl

 

I have used Hylomar for years on valve covers and *never* had them leak again. Years ago you used to get it at the neighborhood auto parts store. Now, its only available online. I love that stuff.

 

The issue with sealants is not whether they work or not but whether the excess inside will break loose and block some oilway. Some (more modern?) engines are more susceptible than others, e.g. Saab specify loctite 518 for the sump gasket for this reason.
Whether it's a problem on older engines is an unknown, I certainly used to use RTV (used to get military grade hi-temp RTV from a defence firm I worked for) and Blue Hylomar and even red Hermitite many years ago on older cars. Nowadays it's a case of why take the risk when there are safe alternatives.

 

Hi All

Dregding up an old thread with request for clarification. I plan on doing a stakedown kit and cleaning the Crankcase Ventilation System out. My question goes to a post Grant Francis made. Do I understand correctly that instead of using a Valve Cover Gasket he recommends just using HiTemp RTV sealant instead? That is to say put RTV on instead of a gasket? What about for the Crankcase Ventilation gaskets? Should one use new copper washers or reuse old or use something else? I am aiming at trying to clear up leaks in these areas while doing the stakedown. Oil is currently leaking from these areas.

 

OK, assumptions from me got a tad muddy.

NO gasket. Only NEW "D" seals, coated with a good layer of said RTV.

A 3mm APPROX bead of RTV around the face of the cylinder head, slide the cover on, and fit a few dome nuts FINGER tight. Just enough to seat the cover, or until you see the "Squish" of RTV from the joint, but NOT tight enough to squish the RTV out of the joint.

Walk away, it is now "beer o'clock" and let this RTV set off.

Now, tighten the nuts etc about 1/2 a turn further and thats it.

The vent snout at the front is a mongrel at best, and I use new gaskets and RTV here, and NEW copper washers.

The rubber elbow on top is also sealed with a smear of RTV, and the filter inside is discarded.

None of this is hard, just fiddly. The apprehension of not using a gasket is the scariest thing, but I have done this for years, and way before Forums and computers were around.

 

Thanks Grant. Couple follow ups. How long is beer o'clock? I drink pretty fast.

Second, do you use RTV underneath the washers of the Valve Cover? How much?

 

The AJ16 engine didn't use a seal on the oil sump, right? If there is debate about which sealant to use, why not just refer to whatever Jaguar specified for sealing the sump and use that on the valve covers as the recommended replacement for a gasket?

 

Beer o'clock is whatever you can get away with, and still get the job done, eventually.

On some I spotted a dob of RTV in the area of the camcover where the washer sits, and slid the washer down, and then the dome nut, then wipe off the excess before it dries. Worked 95% of the time. some engines just bleed oil.

New Jaguar thick copper washers did work 100%, and when they were available I used them, bur=t supply was always hit and miss, and the thinner washers they tried to pass off as OE were basically crap, and I returned them regularly.

Annealing the old was another option, and I did it a few times as a last step, when supply sucked.