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oil leak-pcv system? help!

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Old 04-15-2012 | 07:42 PM
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Default oil leak-pcv system? help!

Okay I have searched a ton and none of i seems to be my problem. So i have a 93 jeep cherokee with 4.0 engin. Last week came out and there was a bunch of oil in the drive way and when i looked it was comming from the air box. Figured something in the pcv system was clogged took both of the valves off and all the hoses cleaned all them out i can blow them all. So there all nice and clean.

Came out next morning still leaking(after driving around the day before) so as i was looking at a buddies xj saw his vales were switch compared to the way mine was set up(the open elbow in the back and the elbow with the other elbow with the peice in the middle in the front) so we swaped mine around. it stopped putting oil into the air filter and leaking but now its leaking from over by the oil filter dipstick area. I think its comming from out the dip stick now. from the pressure maybe?

What im saynig is im lost and dont know what it is. sorry if im being confusing, hopfuly someone understands what im saying and can help!
Old 04-15-2012 | 09:07 PM
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Originally Posted by GRANDLICH
Okay I have searched a ton and none of i seems to be my problem. So i have a 93 jeep cherokee with 4.0 engin. Last week came out and there was a bunch of oil in the drive way and when i looked it was comming from the air box. Figured something in the pcv system was clogged took both of the valves off and all the hoses cleaned all them out i can blow them all. So there all nice and clean.

Came out next morning still leaking(after driving around the day before) so as i was looking at a buddies xj saw his vales were switch compared to the way mine was set up(the open elbow in the back and the elbow with the other elbow with the peice in the middle in the front) so we swaped mine around. it stopped putting oil into the air filter and leaking but now its leaking from over by the oil filter dipstick area. I think its comming from out the dip stick now. from the pressure maybe?

What im saynig is im lost and dont know what it is. sorry if im being confusing, hopfuly someone understands what im saying and can help!
I didnt have the same problem but it was time i replaced all those hoses and elbows.. i just recentely did it. Its pretty simple and cheap to replace all of the CCV system which includes the tubes, grommets, and the pcv elbows which the rear one is the pcv elbow with orfice (has the small hole and its grey) the front one is just a black pcv elbow it should be fully open
I dont know if this helped you at all but it sounds alot like what i just had to do with my jeep
Old 04-15-2012 | 11:22 PM
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Do you feel a strong vacuum at the PCV valve orifice with the engine idling? You should.
Old 04-16-2012 | 06:47 PM
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Originally Posted by Radi
Do you feel a strong vacuum at the PCV valve orifice with the engine idling? You should.
Are meaning if I take it out off the block while still connected to the hoses tho?
Old 04-16-2012 | 11:39 PM
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Originally Posted by GRANDLICH
Are meaning if I take it out off the block while still connected to the hoses tho?
He means take the hose off at the CCV. Turn the motor on and put your finger over the valve. You should feel pressure on your finger within a few seconds.
Old 04-16-2012 | 11:55 PM
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I found a picture that might help:



The rear hose ("air out") should have engine vacuum. You can feel it if you remove the elbow from the valve cover and stick your finger on the end.
There is a small orifice to meter that vacuum, if it plugs up you'll get oil in the air filter box, out the dipstick tube or anywhere else it can find to vent.
Old 04-17-2012 | 12:37 AM
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just wondering i have the same problem but didnt think anything of it and what is the orifice?
Old 04-17-2012 | 12:53 AM
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Originally Posted by vip01hp2
just wondering i have the same problem but didnt think anything of it and what is the orifice?
the little hole on the underside of the ccv. the other is open.
Old 04-17-2012 | 04:17 AM
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Ill check first thing in the morning! And I'm assuming if I don't feel suction from the valve after I take the hose off I need a need valve with the orfice correct?
Old 04-17-2012 | 04:19 PM
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Yup. Just don't replace it with a PCV valve. It's a CCV valve. You'll have to give them the vehicle information for them to pull it for you, and I would suggest a dealer if you dont want chinese crap. If they tell you that you have to buy a new valve cover, just walk away.

and dont forget the grommets
Old 04-17-2012 | 04:25 PM
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Originally Posted by jarhead0415
Yup. Just don't replace it with a PCV valve. It's a CCV valve. You'll have to give them the vehicle information for them to pull it for you, and I would suggest a dealer if you dont want chinese crap. If they tell you that you have to buy a new valve cover, just walk away.

and dont forget the grommets
I don't know how it is where you guys live but here at the dealership its a pcv elbow, there isn't a ccv valve, there's a pvc elbow with orfice (rearone with small hole) and a pcv elbow without orfice (front one with big hole) that's what it is a pcv is something that hooks onto the manifold. I literally just got all this replaced and all of it was from the dealership specified for my jeep.
Old 04-17-2012 | 04:31 PM
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I was down at oreilys looking for them they had the elbow with the orfice but it wasn't keyed like mine is. It was all circled mine has a big and a little side that works like a key.... guess ill have to go to the dealership
Old 04-17-2012 | 04:51 PM
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here's a good write up

http://www.jeepforum.com/forum/f310/...ite-up-733669/
Old 04-17-2012 | 06:42 PM
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Just checked and yes there is suction.
Old 04-17-2012 | 09:32 PM
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Originally Posted by GRANDLICH
Just checked and yes there is suction.
Good. Out of curiosity, are you certain the oil is coming from the dipstick tube and not the more-common oil filter adapter leak? They're pretty close together. You said the oil is staying out of the air filter box now? I'm thinking your CCV is probably working correctly then.
Oil blowing out of the dipstick tube with a properly functioning CCV might indicate other problems, ie: worn rings causing excessive blowby. OTOH a leak from the filter adapter just means the adapter is loose or the o-rings are shot.
What happens if you remove the oil filler cap with the engine running? Do you get smoke or vapor puffing out the filler?
There shouldn't be any pressure there, if anything a slight vacuum.

Last edited by Radi; 04-17-2012 at 09:35 PM.


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