Hey everyone Im new to the jeep world. I recently bought a 93 wrangler with the 4.0L. I went to change the air filter out, and I noticed the air filter housing was completely soaked with oil. And I mean SOAKED! So cleaned it all out and replaced the filter. I realized that all of the oil had come from the breather hose that leads to the valve cover. So I disconnected the hose and put a separate breather filter on top of the valve cover. Then I took the jeep for a spin and smelled burning oil. I popped the hood and there was oil everywhere. It had been coming out of the new breather filter on the valve cover. Can someone tell me what is wrong? I put the correct oil in the jeep and the correct amount. Please help.
You have either a bad pcv valve or bad rings. Start with the PCV valve. Some people suggest pulling the valve cover and cleaning underneath the valve cover to allow it to breath. If it doesn't fix it you can run a compression check to see if the compression is allowing blow by.
You actually have what the call a ccv valve. It is at the back of the valve cover. The hole in it is eather pluged or you have a vacuum leak. The boots for the vacuum might be worn out or dry rotted. That is where you should start. If there is a problem the crankcase cannot vent properly. Good luck. If you can take some pics of the vacuum line connections and post.
Thanks for the replies. I checked the CCV/PCV line leading to the intake manifold and it was clear of any stoppages. The line looks alright, but ill try changing it. I don't understand how that little hose being clogged could cause the blow back of oil that is in my air filter housing. I mean there is a LOT of oil coming though the breather hose.....Just took the valve cover off a min ago and the rockers are extremely
dirty. Lots of built up oil. Is this normal for a 93 YJ with 90k miles? The valve cover is bad also. What is the best way to clean the rockers, springs and push-rods?
I think that I'm am going to take the head completely off and have it soaked in some type of mineral sprites. Than I will get ahold of my dealer and order a new CCV hose. Due to the fact that the boots on the one right now are dry rotted. Thanks for the replies. I'll post back once I figure something out, or come across another problem. Thanks.
If you are going to pull the head you can make your life easier by pulling the drivers fender to get at the manifold bolts on the side. Believe me 1/2 hr. work wil save you tons of cash you end up dumping into the cuss jar.
I will for sure keep it in mind to take the fender off when pulling the head. Thanks. And Yes I have already taken the oil pan off and it didn't look to bad. The crank and bearings had oil on them but no signs of build up. It looks like the bottom end has had proper oil changes, while the top end looks like it had never been changed. I'm thinking the oil drain holes in the bottom of the head are not allowing oil to drain properly. And cause oil build up on the rockers and inside the value cover, because the oil pump keeps pumping oil to the top end and it has no where to go it causes the blow back that I'm am experiencing. Does this theory make sense? And is it worth me pulling the head to clean? Thanks everyone for the feedback.
I personally dont think you need to pull the head. With no ventilation the top end will crud up just the way yours did. Clean it and you should be fine. If you want to run the wet/dry compression test. If the test is good then leave it together and clean it.