87 MJ oil in the air filter problem (blow by)

[DaveB]

My son's 87 MJ has the common oil in the air filter box problem caused by oil blow by. The engine does have high miles on it but doesn't smoke and passes emissions just fine. I fixed the gummed up CCV (constant crankcase ventilation) metering grommet on the valve cover and cleaned out the hose that feeds the manifold and that helped but didn't fix the problem. Yesterday I pulled the valve cover off to clean the inside parts of the air inlet and exit ports. What I found was that under each port is a "tower" that must help keep oil flipping off the rocker arms from getting into the ports. Between the towers and the valve cover is a thin metal reed valve that looks to me like it is supposed to close off the port unless air is pulling the valve open. The two metal valves were covered with deposits and bent. One looked like it had been bent with a screw driver and would never seal well. Does anyone know if these reed valves are supposed to be bent up or sit flat ?

Also I have been searching the net for info on this problem and have found where people has supposedly fixed the oil in the filter problem by using the PCV valve and hoses from an older 258 CJ motor. Has anyone tried this fix ?
Thanks for any ideas.

 

[DaveB]

I ended up doing the pcv valve swap (for an 6 cyl. 85 cj) and so far it has worked very well. I also found some broken plastic vacuum lines and fixed those too. It runs better now and isn't coating everything with oil.