Valve cover clean-up

[Keyav8r]

I took my valve cover off to change the gasket and see how the top end looked. Cleaned up the valve cover including removing the two "stacks" that are under the CCV and vacuum fittings. Found a brass "flapper" under each stack. Unfortunately, when I took the stacks off the gaskets on both sides of the flappers crumbled. I have the valve cover cleaned, painted and ready to put back on but need new gaskets for the stacks? The old gaskets were about 1/32" thick or less. Any suggest a material that i can cut gaskets from that will handle the heat and oil vapor? It's an 88, 4.0L. :help:

[Jeep Driver]

Pics?

[HOrnbrod]

I took my valve cover off to change the gasket and see how the top end looked. Cleaned up the valve cover including removing the two "stacks" that are under the CCV and vacuum fittings. Found a brass "flapper" under each stack. Unfortunately, when I took the stacks off the gaskets on both sides of the flappers crumbled. I have the valve cover cleaned, painted and ready to put back on but need new gaskets for the stacks? The old gaskets were about 1/32" thick or less. Any suggest a material that i can cut gaskets from that will handle the heat and oil vapor? It's an 88, 4.0L. :help:

 

Yes, I lost some of those too when I did mine years ago. On my 91 the gaskets were a clear film, very thin. Just used a very thin coat of hi-temp copper RTV on each side of the flapper for the ones that I lost. Worked well with no problems. In a later post with a pic of my dog, I saw where one of the gaskets went - on the floor. The little bastid probably stole it to play with it. :D

 

[Keyav8r]

Mine seemed to have the thin clear film on each side of a slightly thicker dark brown gasket material that was brittle. Probably from the heat.

Glad you came back with the high temp RTV as it confirmed what I was thinking about doing.

I'll try to get some pics if I can figure out how to transfer them from my phone.

[Harley]

I took my valve cover off to change the gasket and see how the top end looked. Cleaned up the valve cover including removing the two "stacks" that are under the CCV and vacuum fittings. Found a brass "flapper" under each stack. Unfortunately, when I took the stacks off the gaskets on both sides of the flappers crumbled. I have the valve cover cleaned, painted and ready to put back on but need new gaskets for the stacks? The old gaskets were about 1/32" thick or less. Any suggest a material that i can cut gaskets from that will handle the heat and oil vapor? It's an 88, 4.0L. :help:

 

Yes, I lost some of those too when I did mine years ago. On my 91 the gaskets were a clear film, very thin. Just used a very thin coat of hi-temp copper RTV on each side of the flapper for the ones that I lost. Worked well with no problems. In a later post with a pic of my dog, I saw where one of the gaskets went - on the floor. The little bastid probably stole it to play with it. :D

 

 

 

 

 

Maybe the mutt ran outta smokes and was pissed at ya for not rushing to get more.

[cruiser54]

Here's something you ought do while that valve cover is off. It was an unpublished factory fix for oil in the air cleaner on 87 to 90 4.0s..

 

Cruiser’s Valve Cover Mod

 

Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.

 

 

Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.

[lexluthier72]

Cruiser....Does this "mod" also work with 2.5l?

[cruiser54]

I don't know.

 

Let's see a photo of a valve cover turned upside down.

[lexluthier72]

There is a photo on the 2nd page of my "build"

 

viewtopic.php?f=7&t=31908&start=15

[cruiser54]

Looks like it would be a great idea to do the mod.

[HOrnbrod]

Here's something you ought do while that valve cover is off. It was an unpublished factory fix for oil in the air cleaner on 87 to 90 4.0s..

 

Cruiser’s Valve Cover Mod

 

Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.

 

 

Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.

 

I had a little blow-by originally and got rid of it by removing and cleaning up the towers and flapper valves inside the cover, cleaning the CCV orifice, and upgrading to the larger late model CCV hoses and fittings. Just what is accomplished by sawing off the vent towers and drilling the 1/2" hole? Better ventilation? Not questioning the wisdom or non-wisdom of this mod, just curious and what does it do? "A buddy at JeepTech" is the best reference? :dunno: