Oil on a spark plug, what do you think?

DryBones · **Posted:** Sun Mar 29, 2009 7:59 pm

changed the plugs today and found oil on the top half of the threads of #6. Nothing down on the end and no fouling so I am not sure what to do about it. Do I need a compression test on the cylinders or possible valve cover gasket? got about 10k left on my maintenance contract so I want to make sure this isn't anything major before that runs out.

JeepinJarhead03 · **Posted:** Sun Mar 29, 2009 9:42 pm

looks like a valve cover gasket, you can see at the base of the ceramic before the head of the thread theres orangeish brown oil residue prior to the thread stud, looks like it's pooling in the plug hole and seeping through or the threads picked it up on the way out

SoDakJeep · **Posted:** Sun Mar 29, 2009 11:28 pm

mine has done this as well when I changed plugs it was the back right plug #6 I think. Same thing exactly not really sure what to think about it though.

djui5 · **Joined:** Tue Jun 17, 2008 1:38 am **Posts:** 536

Check the engine really good for leaks. Like you said it's probably a valve cover gasket. Very easy and cheap to fix. If nothing is leaking then it's possible someone dumped oil everywhere when filling it with oil

DryBones · **Posted:** Mon Mar 30, 2009 7:56 am

thanks guys. Everything on the outside is dry. valve covers are dusty only. no oil around the edges. Hopefully it's something minor. I am going to check on repair estimates for valve cover gaskets and see if that's covered under my maintenance plan.

BTW, mine is #6 also, that tough one in the back under the bottle. :lol:

JeepinJarhead03 · **Posted:** Mon Mar 30, 2009 11:33 am

I'm tryin to picture DryBones puttin oil in his jeep after an oil change and 'Flingin' it towards the #6

yeah I'm thinkin not :lol:

see if the gaskets snug on the valve cover, it's gonna be hard to peer down the #6 well without a scope

if it's been unsnug too long you'll prolly have to replace it , ya know how it goes

SoDakJeep · **Posted:** Mon Mar 30, 2009 11:11 pm

I guess I haven't done anything about it and I dont seem to be losing any oil. However I do seem to only be getting 9.5-10 mpg lately and it is going to the dealership sometime next week or so. I will let you know what they say.

DryBones · **Posted:** Mon Mar 30, 2009 11:12 pm

thanks! good luck!

tjkj2002 · **Posted:** Mon Mar 30, 2009 11:16 pm

DryBones wrote:

thanks guys. Everything on the outside is dry. valve covers are dusty only. no oil around the edges. Hopefully it's something minor. I am going to check on repair estimates for valve cover gaskets and see if that's covered under my maintenance plan.

BTW, mine is #6 also, that tough one in the back under the bottle. :lol:

The spark plugs do not run through the valve covers on the 3.7.

oddball · **Posted:** Mon Mar 30, 2009 11:36 pm

tjkj2002 wrote:

DryBones wrote:

thanks guys. Everything on the outside is dry. valve covers are dusty only. no oil around the edges. Hopefully it's something minor. I am going to check on repair estimates for valve cover gaskets and see if that's covered under my maintenance plan.

BTW, mine is #6 also, that tough one in the back under the bottle. :lol:

The spark plugs do not run through the valve covers on the 3.7.

Amazing what you'll discover when you open the hood. :lol:

Sorry, couldn't resist.

DryBones · **Posted:** Tue Mar 31, 2009 12:11 am

tjkj2002 wrote:

DryBones wrote:

thanks guys. Everything on the outside is dry. valve covers are dusty only. no oil around the edges. Hopefully it's something minor. I am going to check on repair estimates for valve cover gaskets and see if that's covered under my maintenance plan.

BTW, mine is #6 also, that tough one in the back under the bottle. :lol:

The spark plugs do not run through the valve covers on the 3.7.

Ok, I thought we were once told that the coil pack ran through the valve cover and why there is that rubber seal on the coil. I guess I was misinformed. Now that you have killed that thought how about a possible cause as to why there is oil on the upper threads of 1 plug only?

tjkj2002 · **Posted:** Tue Mar 31, 2009 12:18 am

DryBones wrote:

tjkj2002 wrote:

DryBones wrote:

thanks guys. Everything on the outside is dry. valve covers are dusty only. no oil around the edges. Hopefully it's something minor. I am going to check on repair estimates for valve cover gaskets and see if that's covered under my maintenance plan.

BTW, mine is #6 also, that tough one in the back under the bottle. :lol:

The spark plugs do not run through the valve covers on the 3.7.

Ok, I thought we were once told that the coil pack ran through the valve cover and why there is that rubber seal on the coil. I guess I was misinformed. Now that you have killed that thought how about a possible cause as to why there is oil on the upper threads of 1 plug only?

The coil pack runs through the head.Was there oil on the coil anywhere? If not it came from inside the engine,if so you got a leak in the head or a outside source(if the oil only coil is above the o-rings).

DryBones · **Posted:** Tue Mar 31, 2009 12:43 am

no oil on the coil this time. last plug change there was and the o ring was shot. I replaced the coil at that time. Wish it wasn't that back plug so I could get a good look down the hole.

edited to remove some of my stupidity :lol:

JeepinJarhead03 · **Posted:** Tue Mar 31, 2009 12:49 am

autozone or advanced 'may' have a optiscope you can borrow

it's a big maybe but worth askin

the autozone back in newbern has one but they have a lot of odd stuff ontop of a gigantic masters tool set

DryBones · **Posted:** Tue Mar 31, 2009 12:51 am

JeepinJarhead03 wrote:

looks like a valve cover gasket, you can see at the base of the ceramic before the head of the thread theres orangeish brown oil residue prior to the thread stud, looks like it's pooling in the plug hole and seeping through or the threads picked it up on the way out

Just took another look at all 6 plugs and only cylinder 5 and 6 have that tarnished area on the ceramics of the plug. maybe the valve cover gasket is leaking in that area afterall?

BTW, these plugs were shot after only 30k. Rough cold idle. Save your money and avoid the Iridiums. KJ runs great now with the Autolite Double Platinums.

JeepinJarhead03 · **Posted:** Tue Mar 31, 2009 1:17 am

bah butter fingers see post below

JeepinJarhead03 · **Posted:** Tue Mar 31, 2009 1:19 am

it may be more of a statement against bosch rather than against iridiums

vw bug i did that plug change on a few weeks ago had 3 OEM plugs at 100k, when i say OEM i mean litterally the plugs that were stuck in it at the factory

they were ngk irids, and they were toast..

but they weren't nearly as bad as the #1 plug that you could actually get to without taking off the plenum, it had been replaced at roughly 60k, so it had 40k on it, was the same type plug you got there

and it was absolutley horrid, the ngks had some valleying, but the bosch was so balled back that i thought it had precombusted

i typically prefer autolites but im not completely sold that the ngk irids are as bad as some make them out to be, set thats in mine has about 6k on them now, it has a very slight idle tremble but very infrequently

not to derail over the spark plug type but the oil residue discoloration on the ceramic was what made me think of the valve cover leaking, but unless its pouring down the side or leaking from something down the coil then it may be residue from when they were oil wet from before

it looks like you just had 2 of them with oil tarnish on the cermaic and theyre the ones that have the wettest threads

i'd clean everything, get ya a handfull of o-rings, swab the boots and reapply the electro goo and see how it goes for a few oil changes, pull them again in 2 or 3 oil changes and see how things look

the tips don't look oil fouled, they just look worn out, which from the only expeirence i have with that type bosch being that one plug in the vw i'm still not supprised

while they may not go through the valve cover, and I can't picture the placement in my head, it could run down and make its way through there but i'd think you would have noticed it on the coil boot, i'd clean everything real good with a torn up tshirt and a unsharpened pencil or something and see how it looks after a reasonable interval, i wouldn't be horribly paranoid over it

jg45 · **Posted:** Tue Mar 31, 2009 6:03 pm

My number 6 plug was the same way the last time I changed it. I haven't checked it again, yet.

DryBones · **Posted:** Tue Mar 31, 2009 7:56 pm

hmmm.....seems to be a common thread among the KJ's. Almost like the window regulators. Let's sue them! :lol:

Oil on a spark plug, what do you think?

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