Leaking Valve Cover

[WarWagon]

Cork I wouldn't touch. They leak and allow the bolts to bend the valve covers. Even with perfect low torque install the cork will leak in a short time. IMO the cork has missing dowels to prevent the excessively thin GM valve covers from bending under the bolts. Complete fing time consuming mess to scrape off when not if you pull the covers again.

Rubber maybe.

Even RTV silicone will leak eventually, but, it's the easiest to clean up and generally the easiest to install. It also holds the part down rather than depending on the small bolt area that bends reducing clamping force away from the bolt esp. with heat cycles. The other gaskets are always falling off during install. I have had things get in the way and mess up (Scrape off silicone) silicone valve cover install giving me the privilege of doing it over.

GM used RTV at the factory for most of the 6.5 engines I have torn into.

 

[FellowTraveler]

I'm resolved to replacing all the buttons. I bent the valve cover a little on the top side when I went to pry it off. I flattened it using a mallet and a pieced of wood. I will get a couple pieces of steel to do this the next time. It's not leaking from the top side.

I see on Rockauto they have cork/rubber valve cover gaskets for the 6.5. So, why not use those? Always had excellent results using those on air cooled VW engines.

IMO a custom valve cover one that will not bend so easy would be a nice addition.

 

[Big T]

Cork I wouldn't touch. They leak and allow the bolts to bend the valve covers. Even with perfect low torque install the cork will leak in a short time. IMO the cork has missing dowels to prevent the excessively thin GM valve covers from bending under the bolts. Complete fing time consuming mess to scrape off when not if you pull the covers again.

Rubber maybe.

Even RTV silicone will leak eventually, but, it's the easiest to clean up and generally the easiest to install. It also holds the part down rather than depending on the small bolt area that bends reducing clamping force away from the bolt esp. with heat cycles. The other gaskets are always falling off during install. I have had things get in the way and mess up (Scrape off silicone) silicone valve cover install giving me the privilege of doing it over.

GM used RTV at the factory for most of the 6.5 engines I have torn into.

That's apparently what happened to me...scraped off the RTV silicon during the install. The initial fail was due to the rear valve cover bolt coming loose. The bolt pattern on these is pathetic.

Given that I will be replacing the buttons, now on both sides, I punted and ordered (tirecrawler.com) new Cooper AT3 tires for my wife's 2014 4Runner which should arrive today at the local Allen Tire Shop today. The 4 Runner will be our vehicle for the upcoming road trip. The valve covers and buttons job will have to wait, along with the GMT 800 brake conversion project (still getting the last of the parts for my son's).

 

[Husker6.5]

The bolt spread pattern on these valve covers suck. That's why I don't run the gaskets- they still leak with them unless you use enough goo to glue them to bothe surfaces, now it requires more sealant, and is harder to clean up.

That's why I use Permatex's spray-on gasket adhesive! You spray the lip of the valve cover and the gasket, wait til it's tacky, then position the gasket and it stays in place when you flip the valve cover over to position it on the head. The adhesive forms an oil resitant barrier bond with the gasket. A bead of "The Right Stuff" on the head surface and you're good to go. As far as valve cover deformation and possible leaking, try using something like these, although I know Mr. Gasket makes ones where the wings are a couple of inches longer on each side to spread the clamping force out more evenly to prevent deforming the valve cover and causing oil leaks when the bolts are torqued down: http://www.speedwaymotors.com/Repla...d-Retainer-Set-for-Big-Block-Nova,116969.html

 

[Will L.]

That's why I use Permatex's spray-on gasket...A bead of "The Right Stuff" ..

<--EDITED for space and example..

Why buy a gasket, buy the spray on adhesive,buy the retainers, and take the time of all that- then use the right stuff?
Just a bead of the right stuff and your done. If you feel better putting it on the head instead of the valve cover, ok. But just use the right stuff and be done with no chance of gasket failure or cover deforming.

 

[NVW]

I have two valve cover gaskets sets for free, just pay shipping. They came in the rebuild kits. Oh, and they're Felpro.

 

[WarWagon]

I have two valve cover gaskets sets for free, just pay shipping. They came in the rebuild kits. Oh, and they're Felpro.

Sometimes you have to cover shipping just to get items like this out of your hair. I got a box full of gaskets like this including NV5600 PTO cover gaskets.

I tell you what I double check my intake a lot due to high silicone readings in UOA before I remember how much gasket in a tube I used to put the engine together. This harmless UOA spike is the only downside to it's use.

The bad place to use just silicone is the t-stat water crossover and head block off plates. I get to redo those every couple of years.

 

[dangerousdave]

Bbbut if I seal the valve cover leaks, where is my automatic rust prevention going to come from?

 

[Will L.]

Steering gear box? That's where mine is coming from at the moment.