Oil or Gas on top of intake???

[ZooKypr]

66 Cuda 273 Commando
Holley 600cfm mechanical double pumper & Edelbrock Performer Intake. Setup is 20yrs old. Carb rebuilt about 10yrs ago.
Been having this issue for awhile. Usually only appeared after car sat for awhile in colder months. Attributed it to probably gas that leaked and turned to varnish from gaskets shrinking in colder months.
Today after I go for cruise I noticed a larger puddle than usual. . Does not appear to be oil as it lacks the thickness nor smells like gas. Is it gas that drips from carb and the heat from the intake evaporates the odor and turns into a varnish? Underneath carb felt dry.
. Just throughing spaghetti at the wall here!!.... Insight fellas??

 

[Mike69cuda]

Mine seems to leak oil from an intake bolt and puddle on right rear by coil. I have heard sealing the intake bolts help, but have not tried it.

 

[MoparMike1974]

I always seal the intake bolts with pipe dope. If you dont the oil wicks up the threads and will puddle on the intake. The 4 center bolts seem to be the worst for it.
You may also have gas dripping from your throttle shaft, have seen that a few times before.

 

[Kern Dog]

I always seal the intake bolts with pipe dope. If you dont the oil wicks up the threads and will puddle on the intake. The 4 center bolts seem to be the worst for it.
You may also have gas dripping from your throttle shaft, have seen that a few times before.

Yep....The intake bolts thread right into the lifter valley where there is crankcase pressure. Oil is splashing around and pressure is looking for an escape path....especially if the PCV system is overworked or non existent.

 

[yellow rose]

Yep....The intake bolts thread right into the lifter valley where there is crankcase pressure. Oil is splashing around and pressure is looking for an escape path....especially if the PCV system is overworked or non existent.

The last part of your statement is by far the most important. A quality, functioning PCV does wonders for oil leaks and such.

 

[ZooKypr]

Weird is I don't see any drips or ruins from intake bolt to puddle. Intake bolt is tight. I guess drops of oil can for at top of bolt when driving and splash out forming a puddle. I will inspect PCV. Correct me if I am wrong but good sign of a working PCV is it "rattles" when shaken?

 

[yellow rose]

Weird is I don't see any drips or ruins from intake bolt to puddle. Intake bolt is tight. I guess drops of oil can for at top of bolt when driving and splash out forming a puddle. I will inspect PCV. Correct me if I am wrong but good sign of a working PCV is it "rattles" when shaken?

Just because it rattles doesn’t mean it’s the correct PCV valve. In fact, I can say with 98% accuracy that your PCV valve is not correct.

 

[ZooKypr]

This is my PCV. Replaced once in last 5k miles. I used the original as reference for a replacement.
If wrong, which type / part# are you saying should be on my 273 Commando?

 

[yellow rose]

This is my PCV. Replaced once in last 5k miles. I used the original as reference for a replacement.
If wrong, which type / part# are you saying should be on my 273 Commando?

View attachment 1715727136

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View attachment 1715727139

I’m saying all those part numbers were collapsed years and years ago. The PCV valve was engineered for very specific applications. Over time, the manufacturers stopped producing application specific valves and made what could be called an “average” valve.

The best PCV valve out there is the M.E. Wagner PCV valve. You tune it for your application. A bit pricey but they actually work.

 

[65 Cuda 340]

Might want to check your accelerator pump diaphragm. The black ones won't hold up to ethanol gas and will eventually leak. Happened on mine, anyway. I replaced my black one with the blue gasahol resistant one.

 

[ZooKypr]

I always seal the intake bolts with pipe dope. If you dont the oil wicks up the threads and will puddle on the intake. The 4 center bolts seem to be the worst for it.
You may also have gas dripping from your throttle shaft, have seen that a few times before.

Applied Permatex to 2 intake manifold bolts and the puddling has stopped...THANKS!

 

[ZooKypr]

Yep....The intake bolts thread right into the lifter valley where there is crankcase pressure. Oil is splashing around and pressure is looking for an escape path....especially if the PCV system is overworked or non existent.

Yep!...Thanks!

 

[furrystump]

You said it did not smell like gas and it was not oil. Correct? Are you saying the recess right near the ground wire? It could be water/coolant leaking from the front pair of intake bolts. They are wet bolts.