Leaking intake manifold gasket...

[JR97COBRA]

Some time ago, I ported the heads on the 4.0 V6, including a gasket match on the intake side. It occurred to me later on that the sealing surface on the factory Ford gasket leaves very little room for a mismatch in the ports. It's been using an insane amount of oil lately, which leads me to think that when I bolted the intake down, the gasket may have moved slighlty, causing a leak.

My question is, does anyone know of a relatively slow-setting gasket maker or an aftermarket gasket that would ensure a good seal on the intake?

 

[LukeDog3D]

I've heard that using a wet type sealant like RTV on the lower intake is simply asking for trouble.

 

[Crankcase]

Isn't RTV sealer slow acting?

 

[SteveVB]

I did the same thing when I rebuilt my 91. I used the factory replacement steel gasket with the integral sealing rings. I dont seem to have any problems, but I was conservative wit the grinder.

What gasket did you use? After looking at the Felpro replacement I had I went out and bought the Ford piece. Very nice.

I also didnt cut the lower port much since I couldnt determine how far down the gasket would sit once it was torqued down. I scribed across the lowest port and made them all equal - left it at that. Width I didnt think would be a problem, but depth/height yes. I ground the sides out to the edge of the gasket.
When I matched the intake once again the sides no problem, but the tops and bottoms of the runners were more difficult, I probably was conservative but it was very difficult to determine the final intake to prt alignment with respect to top and bottom of port.

Anyway may not help you but take a look at the Ford gasket if you used the fiber aftermarketr gasket.

Have fun.

 

[LukeDog3D]

I used the fel-pro gasket at first. The motor was blowing white smoke, and there was oil around the spark plug threads and deposits on the electrodes. It ran smooth, however.

Then I stripped it down and got the ford gasket, and installed that. The white smoke out of the tailpipe disappeared. However, gas started spewing out around the fuel rail....I think I have a bad injector O ring or two.

 

[SteveVB]

valve seals?

I doubt its the seals- they are the teflon positive sealing type which in my (limited ) experience have caused few problems if they are installed correctly.

One thought would be that if you have a leaking injector fuel washing the cylinder walls would cause accelerated cylinder wall wear. An oil analysis would quickly clear up this senario.
It may be that the engine hasnt been run long enough to "clean" it from accumulated moisture etc if it has sat for a period. I would fix the fuel leak, and let it run for a while see how things shape up.

Good Luck

 

[LukeDog3D]

Good suggestions.