Ive got a 90 XJ with 186k, today afyer a short trip i popped the hood and found oil on, in and under the air box. Air filter has oil in it. The hose from valve cover to air box has oil inside it as well. This spring i replaced, timing cover gasket, valve cover gasket and water pump gasket, fromt seal as well. When i checked the dipstick the oil on the end looked rusty, which i know is not great. Just looking for tips where to start to try and fix.

 

Likely the tube coming out of the valvecover at the rear is blocked. As a result, the pressure is seeking a way out and blows the crap into the tube at the front, which then starts to faul up your air intake box.

 

Check both hoses that come off of the valve cover, make sure they are intact and not blocked. If those hoses are in good condition, you might be experience blow-by which could be an indicator that there may be some seals worn in the head. Could be, but not necessarily.

Cruiser54 has also written up a thread about how to modify the valve cover to decrease how much oil comes out of the valve cover to the airbox.

In here, I think...

https://www.cherokeeforum.com/f51/cr...x-tips-153657/