Oil dripping off spark plug threads

Hi folks,
Just changed my plugs and one of them had old looking oil mostly on the threads of the plug. Just changed oil a week ago and it’s still clear so I know it must be older oil. I did soak it all up very carefully...any reason why this happens?

 

I think you're over-thinking this. Plugs look fine, probably just a little hair of compression gases working in over time. Do you put any lube on the threads when you install?...that will "bake-up" over time as well. Plug electrode colour looks very good IMO.

 

I put a little anti seize on the threads and a little dielectric grease on the boot, but the same on all. Don’t see how that happens to only one out of four. You don’t think it’s some o-ring seal?
Not sure if it has anything to do with it but I did just switch over a 1999 Tacoma from a lifetime of non synthetic oil to synthetic last week.

 

Oops...looked again at the photo of the plug pocket. There is a gasket/o-ring somewhere down in there that keeps oil from cam/ rocker area from accessing the plug pocket...might be a couple of those weeping. I'm not really familiar with the 2.7 though.

Doesn't look too serious yet though.

 

welcome to TW
do you know how many miles those plugs had on them?

 

thanks! just about 10k miles since last change.

 

i just recently got new ones too that had about 39k miles on them
your plugs look different than the ones i have

 

I would say it is come from were the valve cover seals to the plug pocket tube. Would need to change the valve cover gasket and the o-ring seals around the plug pockets.

 

Those look like the 3.4 l , double ground electrode plug. Don't think the 2.7 takes those.

 

Thanks ! well looks like I have a small project then haha

 

I second this, very likely replacing the spark plug tube seals/gasket things. Not too bad a job at all. Since the valve cover has to come off, might not be a bad idea to measure the gaps at the valves since it's right there and eventually all of the heads will need a rebuild. Might as well get the measurements now while it's opened up

Agree, different spark plug.

 

Spark plug tube seals, nothing major. A nice weekend project!

Make sure to get all the oil off the spark plug and coil boots.

 

an explanation is in order for the differences in the spark plugs. The 3.4 uses what is referred to as a "wasted spark" ignition system. If you notice there are only 3 coils for a 6 cylinder motor. When the ignition coil fires for the cylinder that is on its compression stroke it also fires on its companion cylinders exhaust stroke. There are 2 ground electrodes to compensate for the spark plugs "double duty". A spark plug with iridium or other harder material can be substituted and left in for a longer period but you risk having the plug stick if it is left in for say 100k miles. Now, some peeps are going to say I have had plugs in for over 100k miles and no problems taking them out, well, congratulations. I see it as a false economy, it only takes one stripped spark plug and the associated expense to loose the $60 you saved in regular plug replacement.

 

My stock '92 Harley Davidson is the same. As is the 3.4 l Toyota. Good description Glassman.

Gotta love "spell check" ....glamisman