Oil on spark plug threads

[Dj-Ram17]

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Just took my spark plugs out to check them and the thread of most of them are covered in oil i believe . All except the one in the far left side are covered in oil, the second one from the right is covered the most in oil.(spark plugs are lined up in order) What would cause this? blown head gasket?

 

[TSITurbo95]

Valve seals, valve guides, piston rings, oil rings, etc. Do a compression test/leak down test and post back the results. Have you done a blt?

 

[Dj-Ram17]

Yea i got to go buy a compression tester after work, and whats a blt?

 

[XiKeiyaZI]

Or it could be - Bad VC Spark Plug Gully gaskets, causing oil to accumulate around your spark plug so when you remove them it's getting on the threads.

 

[TSITurbo95]

^ With no oil above the threads? Doubtful

 

[XiKeiyaZI]

Hm, No. That wouldn't make sense would it? Not after being handled, wiped, or anything like that in the common place to hold plugs with a rag or glove. It's beyond common for this to happen. Assuming that the grime in the threads looks old and built-up, the threads themselves are likely beyond dirty and caked with old residue. I'm not sure if you're aware, but the entire thread of the spark plug does not stick into the combustion chamber. Barely any of it at all does for that matter.

 

[TSITurbo95]

Look at those plugs, those things are so clean you could eat off them. Doubt touching them, or handling them will clean them that well good. And the threads are also not sealed from the cylinder, so when oil is on the piston, or walls during the combustion cycle, it would/could blow it on the plug, and up the threads, could it not? But that would not make sense either now would it?

 

[XiKeiyaZI]

......So you're saying that, disregarding that the threads are likely just dirty and grimy, that he's blowing compression past his spark plug threads? Each of them? All the way up every thread, corroding them, gunking them up, and not blowing his spark plug wires off?

A : This is normally how far a plug sticks into a combustion chamber. Any further and it'd impact the piston.

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B : Seriously...Can someone please confirm to me that we blow a considerable amount of compression and oil residue past our spark plug threads? If so, it'll be noticeable while the car is running as there should be evacuation pin-holes in the sparkplug wire boot. If you feel compression leaking there, then yes - you're leaking past the plugs due to either botches threads or bad plugs in general.

 

[Calan]

There is no oil on or under the crush washers, so the oil is most likely coming from within the cylinders. But... that oil on the threads (if that's really what I'm seeing) also doesn't look like oil that has been through cylinder hell. It would normally be much darker from being burned and absorbing carbon. The good news is the plugs actually look very good from the pic, other than being the wrong ones.

Have you noticed any burning oil?

Follow Ryan's advice and do a compression/leak-down test. And change those plugs out for some good $2.50 NGK's.

 

[Dj-Ram17]

I'm loosing coolant and oil. No coolant in oil or vice versa tho, white smoke when i rev and after i rev high it starts smoking lightly at idle, doesn't overheat, and runs fine. Also get some liquid drip from the exhaust from time to time As for the plugs i just bought the car 5 months ago and I haven't checked the plugs, Il be replacing them with some BPR6ES soon.

 

[Bo0sTdTsI]

Last time I had oil on my plugs my 14b was out

 

[Dj-Ram17]

No shaft play on my turbo

 

[Sprnt76]

I have the same problem. Consuming oil at a rate of 2 qts per 2 weeks. Just checked the plugs and they are clean. Just did complete rebuild 1.5 months ago, with a master mechanic. I am thinking its the valve seals, I had the head checked and all was good. But, I looked in beyond the plug hole when the plugs were out and saw some oil that looked new. Don't know but when I took the head off originally I noticed the tops of the pistons showed residue but not moisture Might I be thinking the wrong thing, could it be piston rings?