Has anyone solved the intake leak issue on 350 TPI engines? My '87 and '92 both leak. When new the dealer replaced the gaskets under warranty several times on both and put thread sealer on the bolts. However in both cases I find oil laying on top of the intake between the two center cylinders on both banks. It's possible both are warped, but that seems highly coincidental. The dealer claimed the was too much blow-by in the crankcase. I don't buy that because I'd expect it to push past the crank seals or elsewhere first. I can replace the gaskets myself, but I'd like to know if anything special needs done to make sure it stops leaking! Any help would be appreciated - Thanks!

 

Are you sure that the oil isnt coming from the valve covers? Oil doesn't typically make it high enough to leak out of the intake where it seals with the head.

 

I didn't know there was a leak issue? I would have coated both sides of the intake gasket with rtv, but that's me. Sounds like a valve cover gasket as was mentioned.

 

This concern isn't just common to the L98. ALL SBCs do this when not built properly. Because the intake manifold contacts engine oil, oil seepage UP the intake manifold bolts happens when the bolts are not sealed properly. It has nothing to do with the gaskets. You can remove and reseal the bolts one at a time and not affect the gaskets or gasket sealing. Permatex's Ultra Gray works very well for this. Ultra Black sets up too hard IMO.

I've also seen aluminum components on nearly every manufacturer, be it block, cylinder head, manifold etc that contacts oil actually "sweat" oil due to the aluminums porosity. Rare, but still a possibility.

 

Thanks for the suggestions. I already pulled the valve covers on both and they're dry. I'll try the Permatex Ultra Gray.

BTW - When the '92 was new the dealer replaced the valve cover gaskets trying to solve this problem. My oil leak got much worse. I took it back and they replaced the oil pan gaskets. It still leaked when I got home. I took it back and showed them the dipstick tube was pulled out of the oil pan when they reinstalled the AIR pump bracket for the RH exhaust manifold...and they called themselves Mr Goodwrench?