deltatechx

I drove my '87 XJ w/ 4.0L about 200 miles yesterday and lost about a 1/2 quart of oil, there was a lot of oil inside the engine bay under the filter box and inside the filter box; the filter itself is soaked with oil underneath the CCV hose port. I checked for vacuum from the small CCV hose at the back of the valve cover and it has suction, but the large hose going into the air box has no suction. Is there something in the valve cover that could be clogged? I've never owned a vehicle with CCV, I've always had cars with PCV systems so I don't know much about the operation of CCV systems or what to check.

Thanx

ZachsXJ

the elbow at the back of the Valve cover is probably clogged causing that pressure to push oil vapors into the air box where they're condensing and causing the problem you're having

mycherokee

I have same problem my filter almost dripping with oil (just bought the Jeep). How do I unclog or replace the ccv valve in the rear of the head?

ZachsXJ

It just twists out. You turn it a quarter turn clockwise and it should just pop out. I'd suggest using seafoam or something else to clean it out. Its probably a better idea to just go to the dealer and buy a brand new one

deltatechx

ZachsXJ

yupp. thats it. it should just turn clockwise 1/4 turn and pop right out

rivercrazy

I think if you shake it you should hear a rattle (I may be mixing it up with a PCV). If no rattle its probably just dirty. Spray some carb cleaner or soak it in gas til it rattles.

deltatechx

that's on PCV systems.


I've already removed that piece to test for vacuum. it's not clogged and there is suction when the engine is running.

projectmayhem

what u have is ccv ( a crank case ventilation system ) there is no valve in this system, however u may have a clogged line but what happens is when to much pressure builds up in your crank case due to a clogged line or even burned piston rings ( quick note: made to keep combustion in the cylinder, and if they are bad it lets excessive pressure into the crankcase) which cause oil to be forced outta the valve cover into your intake filter. i strongly suggest not using an engine cleaner in an older engine b/c if there is build up on your valve cover or oil pan this build up will break up and try to be circulated in the engine

ZachsXJ

I know its not a valve, we have CCV systems and not PCV systems in our Cherokees. I've taken my CCV system completely apart and meticulously cleaned all the gunk that was baked on/into it out with seafoam and q-tips. thats what I'm recommending he do. There are no moving or mechanical parts in the CCV system so buying a new one is kinda pointless. It takes some time to clean it out but then it ends up working as good as new. Seafoam works wonderfully in cleaning baked-on oil residue.

BlueXJ

Do a search for "blowby" most older Cherokees have it to some degree. I have pulled and cleaned the inside of the valvecover to make sure the vents were not clogged and replaced the vent lines. It helped some but a new engine was the ultimate cure for mine.

ZachsXJ

Would that be more related to poor maintenance than the age of the engine? I would really like to buy a BRAND NEW car so I can maintain it properly and make it last for an insane amount of time. I know that with every car I've ever worked on they've not even come close to having the proper care.

BlueXJ

It is from mileage and poor maintence both. Mine had 155,000 on it when I bought it and I replaced the engine at 230,000 with a re-manufactured engine. that new engine has had nothing but Mobil 1 in it since breakin and I change it every 5,000 miles. Has about 60,000 on the engine now and I hope to get another 150,000 to 200,000 out of it.

ZachsXJ

Ok, makes sense. I have a question, how in the world do some people who preform meticulous maintenance on a vehicle get an original engine to go for a million miles?

BlueXJ

I am not sure on an automotive engine. I used to be a mechanic for Trailways and we always got a million or 1.5 million miles out of those engines before complete rebuilds. They usually got 3 rebuilds before they were put out to pasture with "metal fatigue".