Valve Cover gasket leak

When changing spark plugs yesterday as my preventative maintenance every 30k I notice slight oil in the passenger side of the coils of my 4.0. Did my research and spoke with my local mechanic and came to terms it’s the valve cover gasket. He will be replacing this Friday doing both while he’s at it. Is this a common issue on the 2nd gen 4.0’s? I check my oil a couple times a week and have never noticed low oil

 

It's relatively common on many engines that have spark plug tube seals for oil to leak into them when they get older and the seals get hard, wouldn't be enough for it to be low on oil but it will eventually cause misfires as the coil boots swell from being immersed in oil.

 

Ok makes sense. So I take it its definitely the valve cover gasket tho correct?

 

The valve cover gasket and the spark plug "tube" seals come as a set and connected together.

To get to the seals the valve cover needs to be removed.

 

I just had same issue when I replaced spark plugs. The valve cover bolt closest to it wasn’t torqued to spec when I checked it. Hopefully that’s all mine was.

 

Sweet yeah my local guy ordered the whole kit to do it all. Like I said it’s just passenger side leaking but he’s doing it all while it’s removed.
I’ve heard it’s a fairly simple task, just don’t have the time to tackle this one

 

A valve cover gasket wearing out is not an issue. It is supposed to. VCG is a wear item with a lifespan.