Hello, I have a 2001 Dodge Durango SLT Plus that has the 4.7l, it currently has a misfire on cylinder 8 and I don't know what the problem is. I have noticed that there is fresh oil next to valve cover, also I have done code read saying it was Cylinder 8 misfire so i took the spark plug out of cylinder 8 and it had oil all over the electrode so I checked cylinder 6 and the electrode was now yellow? But anyways i'm guessing either valve stem seals, or valve cover gasket, or bad piston rings. Would a bad valve cover gasket or bad valve stem seals cause this? Please help me.

Edit: I forgot to mention that it was burning oil so I replaced the pcv valve and it stopped. would this also be a cause? Also I just changed the oil and the oil smelt like gas, or maybe exhaust from bad cats or something?

 

Bad valve seals would foul the plug, I don't think valve cover gaskets would though.

Tan spark plugs means they are burning properly.

How old are the plugs?

 

Only a few thousand miles on the plugs, and thx for the reply ima look up valve stem seals.

 

Ouch. If it fouled out that quickly.... there is an issue. Might consider doing a compression test..... (dry first, then wet)

 

Would it make sense that the injector for cylinder 8 could be acting up dumping too much fuel making the plug look nasty? And then some of that fuel gets into the oil past the rings?
It makes sense in my head anyways.
Injectors are easy to replace. Or swap them between cylinders and see if the problems follows.
I wouldn't think the PCV had anything to do with this because you only have one of eight cylinders acting up.

 

No cylinder 6 has the yellow on the plug and cylinder 8 has oil all over the electrode

 

I guess what I was trying to ask is if the spark plug is just dark from running rich in that cylinder. Making sure you're not mistaking a dark spark plug caused by too much unburnt fuel, for oil.

 

Swap injectors on 6 and 8, see if the miss follows the injector.