So when I first got my jeep 6 months ago I checked the airfilter and part of it was black (like 1") Today I decided to clean the engine bay and decided to check the filter.. The ENTIRE thing was black. Smells like gas to me my girl says it smells like oil. I know I have been running rich. So is the PCV valve the L shaped thing that goes onto the valve cover and runs to the airfilter if so theres nothing in there its a hollow tube. But I cleaned it out anyway. I removed the filter totally and it runs 100% better so I plan to leave it out till I get paid (tomorrow) to get a new one. But would like to know whats causing it before I put a new filter in and destroy it as well.

 

You'll want to research the CCV system on your Cherokee.

It's the other 'L shaped thing' on the valve cover. Clean that one out too.

The ole lady is right... It's oil... (Could have gas in it...)

 

ya normally I would suspect oil.. But it REAKED of gas.

 

Then you have other issues. A leaky injector and/or valve stem seals.

 

The tube to the rear of the cover and the CCV orifice there should be free so it can suck. On older engines the blow-by gets so bad that deal is like peeing in the ocean though. There's a deal in my signature Cruiser came up with on modifying the valve cover inside so less oil ends up in the filter.

Here it is..

Cruiser’s Valve Cover Mod
Most early and even later Renix 4.0s could be bothered by excessive oil in the air cleaner box. A fix from my old days as Service Manager at a Jeep dealership follows. Information was provided to me from a buddy at JeepTech during those days. I don’t believe it ever came out in a Technical Service Bulletin.
　
Remove the valve cover and turn it over. Next, remove the fluted tubes that are now facing you by removing three screws on each. Chop 1 inch off each of them. Then, about a half inch up from the area where you just sawed them off, drill a half inch hole in the tubes so the holes will face the rear of the valve cover. Clean and de-burr/sand all rough edges nicely, clean with solvent, and reinstall. Don’t be concerned about the chintzy gaskets that will probably crumble into oblivion when you remove the fluted tubes. They can go back together without gaskets.

 

Yeah uhhhhh, by the way, don't run without an air filter. They're cheap to replace anyways.

 

Hope it hasn't been 6 mos between hood lifts.

 

running no filter isn't going to hurt **** unless I go somewhere dirty.. And I guarantee it will hurt less then the oil soaked thing I was running. I'm not going to replace something until I fix the issue thats soaking it with oil.. Throwing away money might be fine for you.. But I work min wage 30 hours a week.. Every dollar counts.

And as for 6 months between hood lifts.. No I check my fluids twice a week and clean my engine bay once a month. Just haven't checked the filter lately.

My jeep has 300k miles on it I truly dont care if I blow this motor up. More reason to swap in a small block.

 

Thing has 300k..that's massive blowby waiting to happen run a catchcan and a breather filter.

 

ya 300k rearend was rebuilt so was the front end. misc. the previous owners kept it decently maintained but theres lots of stupid crap going wrong.

 

A filter costs too much money, but looking for a reason to swap in a new engine?

 

no replacing a filter just to get it destroyed for the same reason is 100% waste of money. I can get a small block for pretty much free... and know people to build the mounts for me. Small blocks are easier to maintain. easier to get running. easier to keep running. and can put down a TON more power more reliably then the 4.0 can.

 

You're in the wrong crowd to question the reliability of the 4.0. You're still runnen at 300K....Anyway, good luck..

 

 

Eh, even small bits of dirt/dust in the air can cause accelerated wear on your piston walls and such. Just cause you can't see the dirt doesn't mean it's not there. Just saying.