Oil puddle on LA intake manifold

[Dakota]

Have an annoying oil leak around your small block intake manifold or want to prevent one?  Read on.

I have noticed a small amount (maybe a teaspoon) of oil forming a puddle in one spot on top of the stock intake manifold of my 340 small block.   The yellow arrow in the photo below points to the location of the oil puddle (not my intake - photo came from "For A Bodies only" website).   Over the last year or so, attempts to find the leak source were not successful.   This included periodically checking the torque on the cast aluminum valve covers, putting some gasket shellac on the valve cover gasket, checking the torque on intake manifold bolts, and visually inspecting the intake manifold for cracks.   I had resigned myself to living with the problem as I had more important things to do on the car.

Recently, I watched an episode of "Uncle Tony's Garage" on YouTube where he discussed the differences between the components of the LA engine series which includes the 318, 340 and 360 cubic inch motors.  The man is a fountain of Mopar knowledge, and out of that fountain came a comment that on LA engines the 4 intake manifold bolts closest to the carb mounting flange need to be sealed because the bottoms of the bolts are exposed to splashing oil from inside the engine.  Huh.  I soaked up the oil puddle one more time, then pulled the intake manifold bolt nearest the puddle.  Sure enough, its full length was wet with oil.  I put some thread sealant on the bolt, reinstalled it and went for a 1400 mile drive (that's another story).   No more oil puddle.   

Thank you Uncle Tony!

[jimynick]

And thank you, for sharing that!   

[70rag383]

UTG is amazing with his knowledge and thanks for sharing. Also want to hear about your 1400 mile road trip Love these  stories!

[Dakota]

Also want to hear about your 1400 mile road trip Love these stories.

https://forum.e-bodies.org/general-topics/7/road-trip-ny-andgt-texas/28166/msg313725#msg313725

[MoparCarGuy]

Yes, the intake bolt holes for LA-series small-block Mopar engines are exposed to the oil drainback for the valley.
Here is a graphic showing the areas on a set of T/A 340 cylinder heads. Note the second picture is of an aluminum head by TrickFlow which seals the bolt holes from the engine oil drainback area.

[Chryco Psycho]

Yup , figured that out a few decades ago ....

[73chalngr]

What specific product should be used to solve this problem?

[Rdchallenger]

What specific product should be used to solve this problem?

High temp thread sealant. Same as used on exhaust bolts that go through the water jacket.