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Discussion Starter #1
Hey all I took out all of my spark plugs for a good read and all of them had oil up the threads, this is #1 cylinder and the ground strap and electrode have a tan burn mark which to me seems fine, I just wanted to know if anyone else has had this problem, I should check the PCV valve probably to see if it rattles (good) or not (Bad) thank you, no rush.
https://i.imgur.com/JX8rDMd.jpg
 

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worn rings and or valve stem seals can cause oil to get into combustion chamber and on plug threads. Yours does not look like any big deal.

How many miles on the motor?

If one or more cyl did have oil covered tip/strap than that would be more of a concern where you would want to do a compression test to compare cyl.

check the PCV (read clean it with some carb cleaner even if it rattles)
 

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Could that oil be from the outside? Like leaky valve cover gaskets? Or leaky intake/china wall? Intake leaks can make oil run everywhere. If you think it's coming from the combustion chamber, any smoke? If not, then I wouldn't worry too much. But I would definitely look for signs of external leaks. +1 on the compression test and leakdown test if you see more coking/deposits on the tip of other plugs or if you really want to be paranoid.
 

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Discussion Starter #6
138,000 on a untouched street engine. I'm positive almost all spark plugs had oil on them. On some start ups it would immediately show smoke then go away and never happen while running.
 

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Smoke on startup... ok then that eliminates my outside leak theory. There is definitely oil in the combustion chamber. Certainly check the PCV valve. And it sounds like you have bad valve guides, smoke at startup... then clears up... classic symptom. A bad or clogged PCV valve will make it worse.
 

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Discussion Starter #8
It could come from the outside as this engine has always had a bad engine oil leak. I've done the oil pan gasket, front timing cover seals. I'm the second owner so I dont think anyone re did the intake manifold china wall silicone seal. If I start my car in the garage and drive it out there was a oil drip half the size of a dime pretty fast.
 

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Discussion Starter #9
Valve stem seals makes sense definitely at this mileage and the thousands of hours operating, this engine is probably due. It still runs good, I have aluminum heads and an intake in my garage I think I should start working on.
 

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The LT1, it is common for the intake to head gasket and hardware to relax and suck oil from the valley into the bottom of the ports.

The Corteco- Detroit Gasket is pretty hard even new and just a little release of tension they can leak.

Try checking all the intake bolts ( some have nuts on top holding brackets you will have to remove)

Might not be your issue, but free to try .
 

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Discussion Starter #11
Good place to check I'll see how loose the bolts might have gotten starting from the middle and working in a circle from driver to passenger alternating sides.
 

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Op

run your fingers along the back of intake where it meets the block...if wet oil than the intake is leaking

if the intake does come off, replace gaskets with the FelPro "printo" seal ones (they have blue sealant around the ports. I use Permatex Black Ultra RTV (better for oil leaks IMHO) on the china walls

If valve stem seals than FelPro Viton ones (full jacket)
 

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Did you check/clean your PCV valve yet? I would do that immediately.

As for sealing the china walls, Permatex Ultra RTV is a good option. Another option is to use something called "The Right Stuff".

https://www.permatex.com/products/gasketing/the-right-stuff-gasket-makers/permatex-the-right-stuff-gasket-maker/

Over the years, I basically starting using the original black formula where RTV is called for in all gasket sealing applications. It's been the only sealant that has stood the test of time for me and has never let me down where RTV has hardened or cracked and leaked. It survives expansion and contraction of intakes, especially the china wall area. I've even used it as a light skim coat on paper and cranky valve cover gaskets with good results.

The key to any sealant is to make sure the surfaces are clean and dry. I spray or wipe the area with brake cleaner or a mineral spirit that fully evaporates before applying sealant.
 
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