changed my spark plugs today and found a oily plug

[KerryB]

The spark plug for cylinder 4 was drenched with oil when I took it out. Its been 5k miles since the last plug change. The UOA that was done 200 miles ago was fine. I do not get blow by oil coming out of the crankcase and I checked the compression and all was within normal spec. I do lose oil however when I boost hard.
what could be the causes? could it be normal? When I did the compression test do all plugs need to be removed? because I did it one by one.

 

[JTK]

Could this just have been some oil that had pooled in the spark plug well? I've seen this on many higher mileage OHC engines with deep set, through the cam cover spark plugs. No big thing if that's all it is.

Joel

 

[The Critic]

Check for leaking spark plug tube seals.

 

[KerryB]

Originally Posted By: JTK
Could this just have been some oil that had pooled in the spark plug well? I've seen this on many higher mileage OHC engines with deep set, through the cam cover spark plugs. No big thing if that's all it is.

Joel


i dont think it is. there was a good amount of oil in the well, but it does not look like the oil came from it. it looked like dirty oil, and when i did the compression check there was oil at the end of the piece from the compression checker.

im not 100%, but i hope this is the problem.
im just looking for some other reasons that could be the problem.

 

[parimento1]

most likely spark plug tube seals

 

[Shaman]

What part of the plug was it on? the tip, or the part that doesn't screw in? I had the same problem with a plug change on my beater. One of the plugs had oil above the screwed in part. I'd look at the spark plug tube seals first, do the VC gasket while you're there.

 

[KerryB]

Originally Posted By: Shaman
What part of the plug was it on? the tip, or the part that doesn't screw in? I had the same problem with a plug change on my beater. One of the plugs had oil above the screwed in part. I'd look at the spark plug tube seals first, do the VC gasket while you're there.


it was directly on the end, tip, and electrode area of the spark plug.

 

[Merkava_4]

There are only two ways for oil to get on a spark plug from the inside of the engine:

1. Oil getting passed the piston rings and into the combustion chamber.

2. Oil getting passed the valve guides and into the combustion chamber.

 

[Gary Allan]

Originally Posted By: Merkava_4
There are only two ways for oil to get on a spark plug from the inside of the engine:

1. Oil getting passed the piston rings and into the combustion chamber.

2. Oil getting passed the valve guides and into the combustion chamber.


Yes, and it typically won't look too much like oil. It will look like ash or stalactites ...at least until the plug doesn't fire anymore.

If you're seeing wet oil (the plug would be fine if you wiped it off) with no other residue, then it's probably a plug tube thing.

 

[ThirdeYe]

I agree with Gary. I had a wet plug once (and the inside of the spark plugs tubes were stained with oil) and it turned out to be the spark plug tube seals. They weren't too expensive either, and they were very easy to replace (in my engine at least)

 

[Shaman]

Gary, do you have a better description of this, or a picture. I am getting some white plugs, and think it may be a oil in the cc problem.

 

[Tosh]

Originally Posted By: Merkava_4
There are only two ways for oil to get on a spark plug from the inside of the engine:

1. Oil getting passed the piston rings and into the combustion chamber.

2. Oil getting passed the valve guides and into the combustion chamber.

3. Turbo bearing...

 

[ted s]

WHY are you changing plugs with 5 k miles on them?