Spark plugs covered in oil

[brockdeck]

Hello all,

Today I pulled out my first two plugs to find oil in the tubes and on the plugs. Not much of anything on the back 4.

I know many will point to spark plug tube seals and valve cover seals needing replacement. I am not an experienced mechanic but I do what I can.

My valve cover and tubes were replaced by the dealer at 160k. I am wondering if there is a possibility the oil is in the first tubes and on the plugs due to them not being tight enough, or the valve cover loosening?

I want to change out my wires and plugs. I have new OEM wires, plugs, cap and rotor in hand. But I am afraid to expose my new wires to oil.

Thanks so much.

Wanted to add, there was some oil on top of the first spark plug boot. I am also looking at the possibility it’s just oil spillage when PO changed the oil as well as I?

 

[BILT4ME]

Yes, it COULD be oil spillage, but they would have had to pour it all over to get it there......

Most likely bad tube seals. If the VC is not tight, the tube seals will leak.

That much oil can and will cause misfire. With to change plug wires until the oil issues are resolved.

Could also have come from the spark plugs being loose. We're they loose?

 

[brockdeck]

Yes, it COULD be oil spillage, but they would have had to pour it all over to get it there......

Most likely bad tube seals. If the VC is not tight, the tube seals will leak.

That much oil can and will cause misfire. With to change plug wires until the oil issues are resolved.

Could also have come from the spark plugs being loose. We're they loose?

Are you suggesting a change the plugs and wires despite the tube leak if there is one? Part of me thinks there is possibility the covers not tight since it was replaced and not tightened since.

Here are some photos for those with trained eyes. Also, I didn’t find the plug very difficult to untighten but it was my first time doing this. I torqued it back down to the FSM just to keep driving.

Shockingly, the cruiser runs fine. Keep in mind these plugs and wires are ancient, I have no record of them being changed since 1999 but they MAY possibly have been freshened up.

 

[LINUS]

I'm going to ask, are we worried about oil above the threads of the sparkplugs, or the oil on the underside?

If we're talking above, then tube seals. Valve cover perimeter gasket has nothing bearing on the tubes.

If you're burning oil & we're talking oil below the threads (would need a quantity) - then valve stem seals are old & tired.

HTH

 

[brockdeck]

I'm going to ask, are we worried about oil above the threads of the sparkplugs, or the oil on the underside?

If we're talking above, then tube seals. Valve cover perimeter gasket has nothing bearing on the tubes.

If you're burning oil & we're talking oil below the threads (would need a quantity) - then valve stem seals are old & tired.

HTH

Oil on the top side. I consistently check my oil and burn very little oil between changes. Plugs looked pretty good below, I compared them to a sheet NGK has online, they are just old and worn out it seems.

So looking at spark plug tubes it seems. My understanding is that this is a relatively simple job? I am a noobie.

 

[LINUS]

OK - I'd just wipe the heck out of the wells, blast clean with compressed air (leave the sparkplug in for this) - maybe wipe with a acetone rag as final step & let air-dry.

Wipe clean the sparkplug leads too, button it all up & check it in ~500+ miles.

Dry - some oil jockey dumped a bigmouth jug over the motor & was lazy.
Wet - you can change the tube seals if you like.

I'm betting more on minimum wage oil jockey, the tube seals do decent if the valve cover hasn't been off & back on. If you pop the valve cover then I'd buy all the tube seals & perimeter gasket, FIPG/rtv.
It'll be brittle like the PCV gasket if you haven't yet popped that guy out & back in.

 

[BILT4ME]

I agree with @ Linus. Do what he said.

Are you POSITIVE they changed the tube seals?

In an example, my truck had #6 plug wire swimming in oil. The top of the spark plugs boot was a better plug seal than the plug seal.

 

[Malleus]

Replace the PCV valve while you're at it

 

[Dave 2000]

I note you said the seals were changed at 160k but, you do not mention how long ago that was or the present miles.

Does not look like a recent problem.

Regards

Dave