This is the first time working on my wife's 08' Pacifica 4.0. She is getting a misfire at #5 so I thought I'd change all her plugs.

I pulled #5 and there is oil on the plug and a little bit in the plug well.

I'm assuming there is some type of seal that is leaking under the valve cover.

Anyone ever have this issue?

 

Hi,
First, I have no experience with the 4.0L. But, on many other car types I have changed the valve cover gaskets and they have come with spark plug tube gaskets. According to Rockauto, the 4.0L valve cover gasket set comes with tube seals - see picture. My hunch is that is your problem, at least with the oil in tube. May or may not play into the misfire. Good luck with it.

 

Thanks for the help. I've heard with some motors you don't want to use RTV on the seal. Do you happen to know how to determine this?

 

Hi,

Don't know on the 4.0L, but in the Factory manual for my '05 3.5L, it does not call for RTV on the tube seals. It does however say to use "special tool MDxx" to install the tube seals. Not sure if that is a must or if you can improvise an appropriate tool to seat them. My hunch is you can.