I've notice my valve cover gasket seems to be leaking oil and the stain has been slowly working its way down the back of the engine over the course of a few months. How important is it to replace this? Should I take some time out of my schedule to make sure this doesn't cause any problems?

 

More of a nuisance than anything. Oil leaks can compromise electrical connections if it gets on them. Other than that it's annoying. Shouldn't take longer than 45 minutes to change if you go slow. Very back bolt is somewhat difficult to get to. Make sure to find a good write up to follow and watch the torque on the bolts when you reinstall the cover.

 

took me 30 minutes...super easy. get the rubber gasket not the cork one...

 

ITs not really gonna cause problems but It will make your Jeep stink and smoke when the enigne gets hot. I would just replace it its not that hard... Like JeepDeep said just take your time and keep your bolts in order.

Oh also I have read that there is an issue with the metrial (cant remeber if its the cork one or other one) if you do some searching you'll find a post about it.

 

There ya go he got it!

 

This. Also pick up some new CCV grommets while you have the cover off.

And yes, you should replace it because it will get gunk all over electrical components. For example, when I got my XJ, it was leaking from everywhere possible. This built up a nice layer of caked on oil and other debris all over my crank position sensor, which definitely needs replacing.

But hey, if you don't mind the messiness, then you can put it off. But I would suggest doing it next time you have a free hour. And once again, RUBBER gasket. Don't cheap out or you'll be replacing it again in a matter of a few months.