[blackhemicharger]

Car has been running rough. My spark plugs we're overdue to be changed so I decided to change them while it was parked for the winter and I needed to get it running good for our Florida trip next month. All plugs looked good (other than they looked overdue to be changed)except these two from the cylinder closest to the driver. Any thoughts on what would cause this???

 

[x111103]

So you lost a ground? That would explain some of the running rough. That plug wouldn't fire without a ground. I imagine it's stuck in your converter now. Oil on the threads usually only comes in from above.

 

[blackhemicharger]

Yeah it was an all of a sudden rough running, so I assume that's why. After changing the plugs she is running great. So might it have a bad deal or something that would cause the oil to get there?

 

[Ddaddy]

Yeah it was an all of a sudden rough running, so I assume that's why. After changing the plugs she is running great. So might it have a bad deal or something that would cause the oil to get there?

It's possible that you have a weeping seal back on those plug locations. The only way to be sure is to pull those plugs again in a few thousand miles and inspect...but I wouldn't worry about it.

That location is also where most of the PVC oil condensate is pulled into the engine for combustion so it could also be that. Do you run a catch can?

 

[x111103]

Yeah it was an all of a sudden rough running, so I assume that's why. After changing the plugs she is running great. So might it have a bad deal or something that would cause the oil to get there?

I don't think a bad valve seal would cause oil to get up on the threads like that. To me that is more from a bad valve cover gasket. On the underside of the valve cover is a rubber gasket where each of the spark plug tubes touches it. I think the rubber gasket for that pair of plugs is probably bad. If you had bad stem seals you would typically see a lot of smoke on start up after letting her sit overnight. The oil will have time to leak down past the seals and burn in the chamber.

Ddaddy has a good troubleshooting step though, pull that plug after a couple of thousand miles and tell us what it looks like.

 

[blackhemicharger]

I don't run a catch can but maybe I should start

 

[x111103]

Running a catch can or not has nothing to do with oil on the threads of spark plugs.


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[blackhemicharger]

So should I just order a new valve gasket and swap it out, I here it's pretty easy to do and pretty cheap

 

[x111103]

What did the coil pack look like when you took it out?

 

[blackhemicharger]

The coil pack looked fine, boots seemed to be in good order, looked physically like the rest of them and all the other plugs looked like they had normal wear on them

 

[x111103]

Hmmm...It's very strange to see that much oil on the threads. I would have thought there'd be more on the boots if it came in past the valve cover gasket. You could always take the valve cover off and inspect the gasket. Then you'd know whether or not a replacement is needed.
I wonder if someone before you used grease or oil on those plugs on purpose for some dumb reason. I think we are probably back to the suggestion of just pulling them out again after 1000 miles or so and see what they look like.

 

[blackhemicharger]

I was the last one to change them, there was a little bit of oil on those two when I changed them last time but not nearly the amount. I never really thought twice about it because even when I go 8,000-10,000 miles on an oil change it never is more than a quarter quart low. Figured it was a fluke or something. The car isn't missing at all since I changed the plugs yesterday so at least it is running great. I will plan on pulling the plug when I get to Florida and seeing what it looks like but I'm guessing it will have some oil. I just looked at my records and I was at about 45,000 miles since my last plug change so I was way over.

 

[x111103]

Yeah, that sounds like a good plan. I used to go about 10,000 miles on an oil change and I was never very low either. If you had bad seals you'd know it going that long between changes. It's got to be getting past the valve cover gasket. Good luck, man. I feel like you seem competent enough that you will get it figured out down the road. Got a lot of people on here that wouldn't attempt to change their own plugs, or who'd rather pay someone to do it for them. I'd rather know what's going on under my hood just like yourself.

 

[blackhemicharger]

I feel way better changing my own stuff. I only take it to a shop if it's something I know I can't do