lower intake gasket coolant leak

[markjdinger]

I've been reading about coolant fluid leaks in the 4.0. I have a '95. Seems the lower intake gasket is a common culprit. I want to make sure that I'm understanding correctly. Will a lower intake gasket failure result in a gushing of coolant at the rear of the engine on the passenger side. It is just below the wiring bundle that goes across the top of the intake. I can see coolant shooting out of this area with the vehicle running. It is just to the right of the valve cover. In looking at diagrams, this is the area where the coolant port at the back of the engine is, and I'm assuming the rubber gasket blew out.

Before i take off the intake, any ideas as to why this would be a bad assumption. Many posters with a intake gasket problem seem to have internal leaks.

Thanks.

 

[Runnin'OnEmpty]

The coolant leak is most likely from the lower intake
manifold gasket. There are coolant ports on each end
of the manifold that mate to the head, and if the
rubber seal is leaking on the outside end, it would
show up where you describe. If the seal was leaking on
the inside, the coolant would drain inside the engine
to the oil pan.

When I replaced my LIM gaskets recently, I wiped a
coating of non-hardening Aviation Gasket Sealer around
the outside of the coolant seals. This isn't recommended,
but it made me feel better...

So far no leaks, but don't have a lot of miles on it yet.

 

[markjdinger]

update

It was the lower intake manifold gasket. Removed intake/valve covers and replaced gaskets. Back in action. Thanks.

 

[Runnin'OnEmpty]

Glad you got it fixed, and thanks for
posting the results.

 

[tombstone]

I noticed that quite a few shadetree mechanics on this forum use Permatex Ultra-Black around the coolant ports on both sides of the OEM LIM gasket but, that restricts the sealing ability of a "carrier style " gasket.
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Featured snippet from the web

Equally important, the intake manifold and head surfaces must be clean (no grease, oil or coolant film) and dry. RTV, other sealants or adhesives should not be used around the coolant or intake ports on carrier-style gaskets. ... New intake manifold bolts are recommended.

 

[fast_dave]

I noticed that quite a few shadetree mechanics on this forum use Permatex Ultra-Black around the coolant ports on both sides of the OEM LIM gasket but, that restricts the sealing ability of a "carrier style " gasket.
Search Results
Featured snippet from the web
View attachment 172299
Equally important, the intake manifold and head surfaces must be clean (no grease, oil or coolant film) and dry. RTV, other sealants or adhesives should not be used around the coolant or intake ports on carrier-style gaskets. ... New intake manifold bolts are recommended.

@tombstone

Thanks for the link to the Engine Rebuilder article on "carrier style" intake manifold gaskets - it's a good read!

 

[tombstone]

@tombstone

Thanks for the link to the Engine Rebuilder article on "carrier style" intake manifold gaskets - it's a good read!

Your welcome...