5.7 Spark plug very wet with motor oil

2011 5.7 Crewmax 239k
I've had it 15 months no apparent issue drives just fine imo every day....I had never pulled a spark plug for inspection till today. Both boot and spark plug were soaked in motor oil.
Trying to establish what if any action to take.
Pros: No check engine light/ codes, does not leak any oil externaly along the heads / visually dry heads & pan no oil puddle. Does not consume any oil between 5k oil changes, starts up first crank, smooth engine, has insane amount of power imo...
( My last truck was a 2.7 Taco)
Cons: oily spark plug & boot.
For 239k miles is this typical or a upper head gasket issue.
Presuming it was a worn piston ring wouldn't it have symptoms ? CEL
Also...can't a compression test establish if there is a piston ring leak ?
I'm not in any way a auto mechanic.
What are other possible causes ?
Could it be It simply has to much oil in the crankcase ??? Idk.
Genius me. No picture of spark plug..duuuuuuh.

 

You'll need to replace the valve cover seal for plug tube. It's leaking causing oil to accumulate on top of the plug and seeping down. A few instances of the plug tube not seated fully. Easy to change a seal out though.

 

Does that mean removal of the heads for access ??

 

No. The valve covers sit ontop of the head. Just need to remove a few things ontop of the motor.

 

Clean the motor up good. Drive it for a bit and look for wherever you see leaks. 5.7 engines aren’t particularly leaky in general. Problem areas are cam tower leaks, valley plate leaks and like most vehicles, darn valve cover leaks. Spark plug tubes are in the center of the valve covers and use an o ring type gasket to seal around the tube, which is part of the head. Piston rings are not the issue here.

 

I found a image of the tube gaskets I see how their installed.
What's the worst thing that can happen if I leave it alone ??

 

The oil keeps leaking. You didn't know it was happening before, just monitor and clean up as needed. It's self corrosion coating itself, so that's a plus. Use a "High Mileage" oil next time. They put some seal conditioners in them to help swell older gaskets to prevent or mitigate leaks.

 

I only saw this cause I pulled a spark plug.
It doesn't leak at all. Not visually on the outside anyway. I do use a F.S high mileage oil. I will get it repaired ASAP.
My main concern was that it was something
Catastrophic.

 

I had 3 seals leaking about 5 years ago. It's been good so far. I also run 5w-30 oil. That's a whole different discussion that's all over the forum.

 

I have a couple seals that leak on my truck, I don't do anything about it. I think it's been like that for probably 100k

 

Are y'all talking about the same tube seals ??

 

Yes. They leak sometimes and we all see varying degrees in the amount.

 

So

Rite on

 

Got extra just in case...

 

I had a 77 Corolla that had the same sort of design. They leaked oil as well. The biggest issue was dumping oil into the cylinders when changing the plugs. Too much oil on the cylinder could bend a rod. I would turn the motor over without the plug installed to blow the oil out. It would still smoke when I started it up.