oil on spark plug #6

[KMG]

I just changed my spark plugs with the OEM Denso's on my '06 2wd v6. I noticed that on plug 6 there was a little bit of oil on it. do any of you know what could cause that? everything else is working fine. I really don't want to take it into the dealership for their opinion$.

so far i heard it could be:
valve cover gasket
valve stem seal

 

[fdbyrne]

The only explanation that comes to mind is a head gasket. The number 6 cylinder is usually the one effected by the head gasket issues anyway although I think it's pretty rare for a post-2005 model year to experience that sort of issue.

 

[scw1991]

if it ain't broke, don't fix it. Most likely minute seepage past the valve guides or piston rings.....which is going to happen on every cylinder to some degree.

As long as the plug is not fouling and causing the ECM to throw a code, I would not be too concerned.

Ummm...is oil on the electrode or on the exterior of the porcelain?

 

[nasdamus]

From what i've seen in the past, most likely it's the Valve Cover Gasket. I recently did mine, fairly straight forward. Gasket from Rock, FIPG from Amazon.

 

[KMG]

it was on the on the threads, - it had not appeared to foul the electrode.

I don't think it's the head gasket, due to no additional signs or problems. the spark plug tube/well gaskets seem to be the likely problem - i've heard that if it was the valve cover gasket there would be oil on the exterior rather then inside the plug seal.

 

[KMG]

do you know when the head gasket issues were resolved in the 4th gen 4runners? was 2005 the last year that had those cylinder 6 problems leading to head gasket replacement?

I'm concerned that the oil is an indication that my head gasket is going out..

 

[CookieRoe]

do you know when the head gasket issues were resolved in the 4th gen 4runners? was 2005 the last year that had those cylinder 6 problems leading to head gasket replacement?

I'm concerned that the oil is an indication that my head gasket is going out..

Yes, in theory the issue was resolved by 2005/2006 when it (HG) was redesigned. However, I did see (do a search) on some 06+ models headgaskets dying. Urrghhh.