Fluid in air filter - looks like oil...

Alright, so it looks like old oil. But it is most likely fuel, somehow.

I've got a couple pictures. I had better ones before I cleaned up but realized I didn't have my SD card in my camera. >.<

So here they are:





Now, before I cleaned it up, the throttle body had greenish-tinted fluid around it (you can see some inside the screw heads). The air filter itself had fluid inside it, the same colour as you can see in the pipe. Definitely need to replace the air filter. Would that be it?

BTW, this air filter was installed by the previous owner. I've only had this about a month.

Where is the air filter? That is the TB and a air tube. It sounds like blow-by. Search for blow by on here and you will get tones of info.

basically the rear valve cover hose or elbow gets clogged and now the front valve cover hose blows oil into the airbox, which then sucks the oil in the intake>tb>intake manifold>combustion chamber.

So if I install this new grommet, it'll all be good?

http://jeep.off-road.com/jeep/article/articleDetail.jsp?id=257985

Ok, you have a CCV system that most likely needs servicing.

CCV consists of a filtered fresh air intake that runs from the intake tube after the filter to the front valve cover grommet, then a metered orifice in the rear grommet of the valve cover that is attached to a vacuum port on the intake manifold.

You need to make sure the fresh air intake is clear, that the orifice in the valve cover is open, that the vacuum line from the rear of the valve cover to the intake manifold is clear, and that the orifice in the intake manifold is open.

From the look of the throttle body you have a Renix, and there is a valve cover mod that Cruiser54 posted to help with the problem, see his post here: http://naxja.org/forum/showthread.php?t=1026666

While severe engine blow-by can cause oil in the filter, 90% of the 4.0s that present oil in the air filter are from a CCV that hasn't been maintained.