4.0 OHV Intake Oil Leak - Tips on sealing please

[Jim Jermain]

I have a '00 Explorer with the 4.0 OHV engine. I had the typical misfire caused by a cracked head. I fixed the coolant issue with a new set of heads, but the intake manifold is leaking a small but noticeable amount of oil at the back where it mates to the block. I purchased a new Felpro two piece intake manifold gasket set and plan to tackle the repair this weekend. I'm wondering if anyone has some tips on getting a good seal. I purchased a tube of Permatex "The Right Stuff" because I've read this a good sealant. I did use it the last time and really cleaned the surfaces well before installation. Just not sure why it didn't seal. Maybe I added too much sealant or not enough. I really appreciate any tips you may provide.

Thanks,

Jim

 

[Runnin'OnEmpty]

FelPro has discontinued the 4-piece intake set
because the end pieces tended to raise the
manifold and encourage leaks. The 2-piece set
uses a bead of sealant across the front and back
of the manifold to seal.

The only tip I know is just to take your time in
applying the sealant with an even bead. I also
let the sealant set up for a few minutes before
setting the manifold, being careful to not
disturb the sealant. Easier said than done, I know.

You might also check your PCV system, especially
the valve. There's no pressure on the lower manifold
and therefore it shouldn't leak, unless the engine is
building crankcase pressure through a sticking PCV
valve.

Felpro supplies a tube of black sealant to use on the
manifold, but I suspect it's about the same as the
Permatex. Either one should work fine...

 

[J_Train]

Do exactly what Runnin'OnEmpty said with his tip. And check that PVC to make sure it's not clogged., as far as sealant goes I prefer the grey Motorcraft sealant. I can get you the part number if you'd like.

 

[Jim Jermain]

guys thanks for the tips. I will certainly check the PCV system. To do this in the past I've simply pulled the valve from the rocker cover and made sure there was vacuum. Is that about it or do you have any additional tips on checking the PCV system? Also if you have a chance I'll certainly take the part number for the Ford gray sealant.

Thanks again!!

 

[J_Train]

Part number is TA-29. It's kinda pricey but it's the best I've seen. I believe it's $20 give it take a few bucks. I use it on anything that needs to be sealed. Intake, rear diff cover etc.

 

[koda2000]

if there's any doubt about the PCV valve, just replace it. having suction on the hose doesn't really mean much. be sure to buy a motorcraft replacement.

 

[Jim Jermain]

Fantastic, thanks again for the great tips. I'm off to my local Ford dealer for the PCV and sealant.

Happy Holidays,

Jim

 

[J_Train]

Your welcome, happy holidays to you too.