I'm asking this again (I know, it's insane to expect different results) but from where will an intake manifold leak?

Q1) Can an intake manifold leak engine oil?

In looking at pics of the gasket set, there are two that seal up against the heads (one each) and two more small cork (maybe?).

Q2) What/where do these other two pieces seal?

 

Yes it can.


Oil can leak from the "china walls" where the cork gaskets are supposed to be used. They'll usually fail and ooze out thereby allowing oil to building up and trickle out. I just use RTV....


Read this please: https://www.ford-trucks.com/forums/1...rom-390-a.html

 

Thanks, that must be what is happening on my truck. The top/back side of the C6 was coated in a half inch of oil/dirt. The front of the block too. My oil leak went way when I put new Valve cover and oil pan gaskets but came back when I washed everything. Shouldn't have washed anything.

Is it true the valve covers have to come off too?

 

Washing the engine and transmission did not cause your leak. Replacing the valve cover gaskets was the right first step to take. And washing the engine will help you trace the leak.
The intake seal to the block is not a pressure seal. You might try re-torquing the manifold. That will pick up a couple of thousands on the seals and you might idle more smoothly. Can't hurt. Otherwise live with this common problem or pull the manifold and replace the cork with RTV per Hio.

 

Ya, I wouldn't mind living with it but it leaves a small puddle of oil everywhere I go. Well, something does. I've been fixing leaks for a while now. Oil pan, valve covers, C6 o-ring/gasket/seal (that was a mother.)

The engine oil leak was gone after doing the oil pan and VC. Probably cuz everything got clean and it just hadn't run down the engine yet.

What RTV BTW? I typically use the black stuff. I like my RTV like I like my women.

 

Sticky and smellin' like vinegar???


.........Permatex Ultra Black 82180

 

Doooooodddd . . .

 

The Right Stuff by Permatex. More expensive than typical RTV but it's the best stuff I've ever used. Doesn't have that vinegar smell, not as slimy as RTV, it has a sort of dull appearance in comparison and is thicker-bodied.

I'm not a fan of using silicone or other sealers in place of intake manifold end gaskets. The tendency is to use way too much, thinking that more is better, and ending up with the excess squeezed out inside the engine where it can break loose and get sucked up by the oil pump, or wind up in other places where it's not wanted. Seen it happen too many times.

On the other hand, I'm not a fan of 1930s technology cork gaskets either. Not sure if rubber ends seals are available for FEs, been a while since I've worked on one.

 

2x Dan. The main stream tells us to use a bead of RTV on the "China Walls" front and back. I also am not a fan of this. I always use Permatex High Tack to stick the cork gaskets to the China walls. Then a real thin layer of Black RTV on the tops of the gaskets. Also in the corners where the China Wall gaskets meet the Intake manifold side gaskets.

 

Why are the front and back called China walls?

 

+1 on The Right Stuff. I have used it to fix GM V6 head rot from the valley gasket de-laminating. You only realize it's an issue once the head(s) have eroded allowing the coolant to finally leak. Cleaned the area with Brake Kleen after removing any rust/corrosion with a stainless steel brush, fill void with TRS and assemble with new gasket. It will outlive the rest of the car. I'm a fan for life.
I also share the concern on using the 'poop' method of applying RTV of any type. The ooze drips will eventually separate and end up in the screen of the oil pickup tube. I did a post mortem on a 5K rebuild that started losing compression. Bunch of RTV drips in the pickup tube choking out the oil. Oil light flickered occasionally and they thought it was wiring. I like a 2mm crown or so. Then just a little pops out just to let you know it made it all the way across.

 

FE intake manifold gaskets were sold as a kit (C3AZ-9433-G replaced B8A-9433-A). These gaskets came loose in an envelope, the flap used adhesive to seal it.

Adhesive dried out very shortly, flap popped open, causing the two cork gaskets to begin to shrink.

The usual method before installing cork gaskets was to soak 'em in hot water for several minutes which caused them to expand.

'Course, once installed, the cork dried out, so they shrank again.

FE's also used cork valve cover gaskets. Beginning in 1966, rubber valve cover gaskets were available, but were only sold at the parts counter as "service part replacements."

Old British vehicles are notorious for leaking oil, as they used cork gaskets everywhere. They also came with horrid "Prince of Darkness" Lucas electrical parts.

 

So if cork is a problem, can I just use them to cut out some paper gaskets? I have sheets of the stuff in different thicknesses. And since this stuff has been in my garage for years, it couldn't be more dried out.

 

Because with most engines they are curvy like the real China Wall.

 

Paper gaskets won't be any better and where you will find thick enough paper gasket material, I dunno. Use adhesive instead.