...Wet oil, as opposed to black, charred, burnt-looking.

So I changed my spark plugs today on my 2007 v6 @ 67000 miles. Last time I changed them was around 30000 miles.

I replaced the factory ones with Autolite plugs @ the 30000 mark (not the best... I know. Noob behavior). This time I changed them with Denso plugs.

EDIT: Not sure this is relevant, but I recently noticed the coolant level is low; as in I need to refill it within a week. See my post further down.

Here is what 5 of the 6 plugs looked like...

EDIT: The first one quoted by scottji is different; I tried to get a better picture here.


All completely dry. Anything that may appear wet in this picture is simply "charred".

Here is what 1 of the 6 plugs looked like...



Covered in oil. From the threads of the spark plug, to the nut-part where the socket wrench hangs onto.

Looking at the front of the car, it's the cylinder on the right, furthest back, closest to the driver's seat.

Not sure what's going on here. Never had any check engine lights. Never had a loss of power (that I know of). Engine runs smooth as butter, aside from the infamous ticking and shaft thunk every now and then. I don't recall having oil like this on the spark plug when I last changed them. I torqued them all 13-15 ft lbs.

Any thoughts of what is going on? Did I simply not tighten that plug enough last time? Anything problematic? Thanks!

Full disclosure -- I have NO idea what this means on a Toyota 4Runner. However, oil in the spark plug hole is a fairly common problem on BMWs that I am familiar with. It signals a bad valve cover gasket. The gaskets on the BMWs have one part that seals the edge of the valve cover to the rest of the engine, and a series of rings that sit around the spark plug holes, and seal off the holes from the valve cover gasket. When the gasket material on those interior holes get old and brittle, oil will begin leaking into the spark plug hole. You want to fix this because it can cause problems with your ignition coils.

Check some parts websites for a valve cover gasket for your car and see if it comes with a series of three little rings that sit in the middle. If so, my vote is to replace the VCG and see if that helps.

I think that is the #6 cylinder where the V6's have head gasket issues.

Crap. Sounds like I need to do some research then. I really was hoping it was something dumb and inexpensive.

It's not even my truck and I hope you're wrong......

I think you're right though from everything I've read.

To think how proper I keep this thing... for something like this to happen...

I'm trying not to freak out.

Now that I think about it... I recently noticed the pink coolant is near the "low level" line... haven't touched it or refilled it since I got it though (@18000 miles).

Yep. Oil in plug. Low coolant level. Those two together are a pretty good indicator of head gasket issue. The low coolant level is caused by the coolant slowly seeping into the cylinder.

That sucks. Good karma to you. Have it checked out.

This prompted me to look around a little, and yes, there are at least 3-4 cases of head gasket issues. Found 1 that was a cracked head - but there were a lot of issues like rough idle, CEL, etc..

Hopefully it's "just" a gasket - if anything.

That really sucks.

Keep us up to date - and it's something else to check for when we replace the plugs.

There are about double that documented on the internet.

I'm sure there are at least a few more....its' what I found on a quick look around.

Yeah I knew the coolant level going down isn't a good thing, however I didn't know what oil in/on the spark plug meant.

I'm going to try to dig up as much as I can find now. I'll keep this updated. Maybe I'll take out the new plug again after I've driven a couple hundred miles and see what it looks like?

I don't know. Any suggestions as to what pictures that I could take of the engine that might possibly help out?

So, Changing the plug isn't going to help. I know it would sure be nice to change the plug and that it would magically be better.

Coolant literally destroys an engine. The sooner you get it looked at the better. Don't hold off, hoping it will get better.

That's not what I meant. I just changed the plugs right before posting this thread. I meant that I will just pull that one new plug (in cylinder #6 I guess?) and check to see if its covered in oil again after a hundred miles, versus the 37,000 miles it was since last time.

Yeah it's sounding like this is going to be taken to the pro's.

Could be similar....Oily spark plug @ 60k service - Toyota FJ Cruiser Forum

That sounds exactly the same with the back, driver-side plug being oily. Do you know how involved it is to replace that valve cover gasket they mentioned?

I'm still not sure why my coolant would be low though.