I have a well cared for 2002 Montero Ltd. with about 95k miles. I just cannot stop the small oil leaks.

My first leak was on the passenger side a couple of years ago. I changed the rear cam bore plug o-ring and it stopped. I had an oil sending unit leaking...changed that.

Now my leak is on the driver's side. So, I set out to replace the rear cam bore plug seal on that side. Well, turns out I couldn't easily get it off as its sealed with sealant due to the cam sensor being on that side. Also, I confirmed that it was NOT leaking anyways.

So my leak is dripping from the rear manifold stud/nut. I've layed under the car looking at this longer than I should admint, and just can't find evidence its coming from the valve cover gaskets. Truthfully, it looks like its coming from the head gasket. Is this possible?

Should I replace the valve cover gaskets first? If I do, how difficult is this and what else should I replace while I'm doing this? Spark plugs and wires?

Thanks for the help! Hoping to keep this running as long as I can. Just installed a full Old Man Emu lift kit that can't go to waste!

 

I'd try to replace the valve cover gaskets first. That is a very common cause of oil leaks, especially if your leak is dripping on exhaust manifolds. While you are doing this job, make sure to replace spark plug seals. Some valve cover gasket kits come with those, some don't. Just make sure you have them.

 

I recently got an '04 Endeavor with a 3.8L V6. Had oil leak, could easily see drips from the front valve cover gasket and the rear was also leaking. Just replaced those Sunday and now I still have a leak on the driver's side so I guess my cam bore o-ring needs replacing (just came on the site to research that). Hunter is correct, while doing that, also replace plugs and the plug seals. Mine were swimming in oil, even though it still ran OK. The other thing I wanted to mention is if your engine is the same/similar to mine, you'll also want to replace the main plenium gasket (upper intake, rubber gasket, 6 circular gaskets each connected to each other) which I got for $8.97 from CarPartsWiz off EBay, their p/n CPW3483.
Well, gotta go watch the new Cavs and LeBoob exact revenge on OKC for that last blowout a few weeks ago. Good luck with the leak.