Oil leaking out spark plugs

atenhuisen · Mar 9, 2018

1956 Ferguson TO 30 Continental Z129 leaking oil through spark plugs threads but nothing coming through exhaust. Anyone experienced this and have suggestions on causes and repairs?

Bob · Mar 9, 2018

What you are seeing is probably NOT engine oil, but rather condensed combustion byproducts.

The plugs are obviously not sealing tight to the cylinder head.

Not matter WHAT condition them engine is in as to burning oil or not, nothing should be sneaking out past the sparkplugs.

Gaskets missing?

Plugs snugged down on debris?

?lugs damaged, or sealing surface surrounding threads in the head damaged?

old · Mar 9, 2018

I agree with Bob you have a plug gasket/seal ring problem and or it is running to rich and you have black unburned gas being pushed out

DoubleO7 · Mar 10, 2018

Been there done that.

Replace oil leaking plug with a new plug.

One of mine was leaking black stuff out around where the steel ends around the plugs ceramic part.
The sealing material between the ceramic and steel shell failed.

atenhuisen · Mar 13, 2018

(quoted from post at 09:41:08 03/09/18) What you are seeing is probably NOT engine oil, but rather condensed combustion byproducts.

The plugs are obviously not sealing tight to the cylinder head.

Not matter WHAT condition them engine is in as to burning oil or not, nothing should be sneaking out past the sparkplugs.

Gaskets missing?

Plugs snugged down on debris?

?lugs damaged, or sealing surface surrounding threads in the head damaged?

Thanks for the info. We tightened the plugs some more than I dared to prevent damage and it stopped. Not sure how to stop the unburned fuel though. The engine starts and runs great other than blue smoke. Hadn't run since 1985. Going to check carburetor adjustments. It was replaced but never adjusted. Hopefully that will clear up the unspent fuel. Oil rings will need to be replaced I believe.

old · Mar 13, 2018

Blue smoke is oil and if it sat not running for year and you got it running good chance it has stuck rings and you need to give it an ATF treatment. Put a 1/4 cup of ATF in each cylinder and let it sit a week. Put he plug back in while it sits. Pull the plugs and spin it over o clear the cylinders of any left over ATF and then fire it up and run it for an hour or so and see if the smoke clears up.

Oil leaking out spark plugs

atenhuisen

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Bob

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old

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DoubleO7

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atenhuisen

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old

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