oil in air filter fix

[89ltd]

I have an 89 cherokee ltd with 4L that has been blowing oil in the air filter for some time now. I have read all the threads on this , cleaned the ccv vacum hose and the valve cover etc and still it blew oil out the breather tube at highway speeds. It has a 100,000 on it and runs great so I figured the rings were not toast yet. Yesterday I changed the oil figuring it was to thin or something, went down the highway and the same thing happened, oil all over. I put a vacum gauge on the end of the ccv hose ( the one that goes to the valve cover at the back of the engine) and it showed good vacum. Then I tried taking off the ccv hose and blowing through it, I could blow through it but there was some resistance. I cut the hose in several pieces and there it was, carbon gunk all over . I cut the section of hose two inches from where it goes into the valve cover and ran a wire through it to clean that little piece. I used 1/4" gas line for the rest of the hose, it slides on nice and firm. Took it for another run and not a trace of oil anywhere. I guess the old hose had good vacum, but not enough volume , even though I blew carb cleaner in it and compressed air. Now at idle, I could put my thumb over the breather hose and feel the suction. Life is good... P.S. the valve cover gasket has to be good , if it leaks, you will loose vacum there as well, I used rtv sealant on both sides of the gasket. Hope this helps some of you kids out.

[badron]

BEST I could tell you is do a Com Test. At 100k you should be OK but testing is the only way to know for sure. They can come bad right from the factory.

[89ltd]

Originally Posted by badron

BEST I could tell you is do a Com Test. At 100k you should be OK but testing is the only way to know for sure. They can come bad right from the factory.

I don't understand what your saying, I fixed the problem and I'm just passing on the info to others, I know a lot of people have scrapped thier jeeps because of this. Its impossible to clean out the (ccv) old vacum hose, it should be replaced with a new one, but thanks anyway. Another thing I did was drill out the white plastic part of the old ccv hose that has the (or should have) the 2.6mm metering hole with a 7/64 drill making it about 2.8mm. This helps out an old engine a bit. I think drilling it to 3mm would be perfect but I don't have that size. I think the mistake most people make is they clean the ends of the hose out and blow it out a bit but down the line in the center of the hose , if there is any amount of carbon, they no longer have a 2.6mm hole needed to create the suction to keep the oil out of the air box. That stupid little ccv hose is about $45 bucks at the dealer, thats why I cut the old one at the very end and used the 1/4" fuel line for the rest of it.

[pat8942]

You hit the nail right on the head,I wanna barf everytime someone tell a person that the rings are shot,show's how little they know.