Oil on plugs?

[jhower08]

today i pulled out my plugs to check them. all of them were alright except the one from the cylinder closest to the fire wall. it looks like it has oil on it. the car runs pretty good and all, besides the fact that im getting 15 - 16 mpg (eta with chip on 91 octane and stock 2.93 lsd) so here are the pics, do you think its oil? if so what is causing it, what can i do about it, and is this the reason for the poor mpg?

[craz azn]

Holy blurry pics.... LOL well.. if the oil is on the electrode, I'd bet valve guides and/or seals are somewhat tired. Not sure if f-ed up rings would cause this too, somebody correct me on this pls.

If its one the outside of the plug, like the white part, I'm willing to put money on the valve cover gasket is leaking.. prolly the only place it might be able to get oil from near there...

My car goops up my #5cyl plug all the time lately, so I just switch em around periodically to avoid the one from starting to misfire.... had it happen once, it came during my first AutoX a couple weeks ago. Not to worry though for next year since I will have a rebuilt motor come spring:)

[JasonC]

Holy blurry pics.... LOL well.. if the oil is on the electrode, I'd bet valve guides and/or seals are somewhat tired. Not sure if f-ed up rings would cause this too, somebody correct me on this pls.

If its one the outside of the plug, like the white part, I'm willing to put money on the valve cover gasket is leaking.. prolly the only place it might be able to get oil from near there...

I'm with this guy, a broken ring will cause this to plus you would see oil in the exhaust if it was a ring, but i can't tell if the oil is on the electrode from the pics.

[jhower08]

im not too sure, ill pull it again tomorrow to see if its on the electrode. this engine sat for a really long time and leaks oil from the valve cover so i guess ill replace that anyway.

[matte30is]

Check the tightness on your valve cover nuts. Mine sat for 2 years and a few of them were so loose that I could just unscrew them with my fingers. I had the same oil leakage on the cylinder closest to the fire wall as well.

[jhower08]

alright thanks alot ill try that tomorrow

[jhower08]

Check the tightness on your valve cover nuts. Mine sat for 2 years and a few of them were so loose that I could just unscrew them with my fingers. I had the same oil leakage on the cylinder closest to the fire wall as well.

did you have oil on the threads of the plug as well or just on the white part?

[jhower08]

its not the valve cover gasket guys. i guess its the guides in the head. is there anything i can do about this besides replace the head. the etas are slow but imagine having one that runs on 5 cylinders... i need help. poor gas mileage plus super slow car = bad. i could handle the lack of power if i was getting 30 mpg but im getting 15. i really really need to do something.

[ivo316]

Give it a try getting a "hotter" plug, this will burn the oil and make your engine run better.

But (shitty pics BTW), the oil on the thread must come from the outside (while pulling the plug through an oil puddle).

Oil in the electrode (when burning) does not look like yours, it's basically a black carbon like goo).

So, first, start your engine with the plug (a new one) out, and ground it and see if you have a spark, maybe the cyl is not firing and oil and gas will flood in there if you don't have a spark.

If the plug does not fire, try the plug wire or the dist cap.

Good luck

[OSM e30]

if it were valve seals would the cyl lose compression?

[euroshark]

No, it would just leak oil down from the top of the valve, and that will mix with the fuel and air as the mixture enters the cylinder. My bet goes to valve guide seals since it sat for a long time. Broken rings are not common, especially if the motor has been sitting... Either valve guide seals or valve cover gasket.

[jlevie]

The pictures are so bad that I can't tell if the electrodes are carboned up. But what I can see looks like oil on the body, which would be an external leak (valve cover gasket).

[OSM e30]

i have the same problem as this guy same cylinder also but i checked my compression and my compression is really low on that cylinder is mine the piston rings? or can it be the valve seals?

[jhower08]

update: so im deffinately getting oil on the electrode. and this past weekend i pulled the exhaust manifolds off to replace the gaskets and i discovered oil in the exhaust port of this cylinder. this leads me to beleive that my car is only running on 5 cylinders and that would be why my obc says im getting 16mpg and even though my rpms are steady my car shakes like a bitch. so is there anything that i can do to have my car fire on all cylinders like putting a hotter plug in or anything like that? help is greatly appreciated.

jason

[JGood]

You're not running on five cylinders. You are getting spark on all 6, that spark plug is working. The oil is in the combustion chamber because a piston ring is likely broke. This lowers compression in that cylinder and when that cylinder fires, it basically isn't making as much power as the other ones, and you feel that in the way the car runs.

There's nothing you can do besides rebuild the bottom end.

I still don't think you are getting 16 mpg. Have you actually reset your trip meter, used almost a hole tank and filled up again, and calculated what you are actually getting?

You cannot go by the OBC or MPG needle.

You don't have a O2 sensor, you likely have a broken ring, your engine probably has over 200,000 miles, I wouldn't expect much more then 20 for around town driving.