Engine oil in the spark plug wells of a 4.6L V-8?

[SyberTiger]

I'm in the middle of a intake manifold replacement and have disconnected and taken off everything necessary before removal of the factory intake manifold. My last step before I got to this point was to removed the Coil-On-Plug (COPs) and I noted what I thought was light engine oil on the outside of the #3 and #4 COPs. The #7 COP had significant wetness around the top of the rubber boot and the #8 COP was filled up with a liquid that initially I thought was motor oil.

Has anyone experienced this type of engine oil leak? Is it likely the valve cover gaskets leaking...OR, am I just mistaken and it's coolant? It has the color of mildly dirty engine oil...it's certainly not green in color but it seems that it's not quite as viscous as motor oil. The smell doesn't provide any clues...it does not have a strong antifreeze smell.

Yes, the reason why I'm replacing the intake manifold is because I had previously observed some green coolant on the of the engine around the #2 or #3 cylinders as I recall. I'm just surprised it's the #8 cylinder I'm seeing all the liquid accumulating in the spark plug well.

This video has comments regarding coolant leaking and running into the #8 spark plug well. Maybe that's the problem?

 

[SyberTiger]

It turns out it's just yucky coolant that had filled up the #8 well right up to about the top of the insulator. I verified it was coolant by dipping a Q-tip in the mystery liquid then lighting it on fire and comparing it to a Q-tip dipped in motor oil. Obviously the coolant did not burn but the oil did. Anyhow, the whole reason I'm replacing the intake manifold was because of observation of a coolant puddle on the other side of the engine so this just verifies what I already knew...I need to replace the intake manifold, dummy!

 

[ROBinGa]

Excellent tip on the testing of that fluid to rule out oil being your culprit. Looking forward to your follow up write ups and pictures if you can.