2005 V8 wet oil in one spark plug

[Propaganda]

Hi, I have a 2005 V8 4runner. I changed out all 8 spark plugs today and notice one had wet dark oil on it. Should I be concerned? I know V6 had headgasket issues. The truck runs fine and doesn't throw any check engine codes. Thanks in advance!

The location of the wet oil spark plug marked below (facing the engine)

X (oil ) X (fine)
X (fine X (fine)
X (fine X (fine)
X (fine X (fine)

 

[Propaganda]

I'm going to buy a compression tester kit next weekend and see if I can find the problem.

 

[BlackWorksInc]

Was there oil on the actual sparkplug body or the sparkplug gap portion? the reason I ask is that it is common for the spark plug tube to fill up with oil when the valve cover gaskets starts breaking down/failing, usually towards the "hotter" (closer to the firewall as they are often the last in the coolant circuit) cylinders.

If there is indeed oil in the cylinder itself, this could be normal as many vehicles will ingest a small portion (some more than others *cough*BMW/MB/LR/GM/ect*cough* ) multiplied by the years and miles the vehicle has could look like its leaking oil into the cylinder. To verify for sure I'd run a compression test and also perform a cylinder leak down test if possible to verify that the cylinderhead gasket is not leaking (I would recommend leaving the radiator cap off so you can see if the coolant bubbles when you perform the lead down test.)

Let us know how it turns out.

 

[Propaganda]

The wet oil was only on the spark plug threads. Nothing above it in the tube. I'm waiting on the kit I'll keep you guys updated. Thanks for the response!