This mule has oil in the air filter housing. I am thinking that maybe there is some type of crankcase ventilation system that is not working correctly? Any ideas? Thanks!

 

Most crank case vents lead to the air box so fumes/gasses can be sucked back in and recirculated to keep from emitting fumes to the atmosphere. Kinda of an epa thing which is good.Too much oil in the engine can also cause an excess of oil mist in air boxes,filters. Plus not checking air box/filters often enough can surprise people on amount of accumulated oil.Plus most air boxes have a drain tube or plug for this also.