Not diaphragm, orifice

 

Which engine? The YJ 6cyl, 4.0 dies not have a PCV valve. It uses a metered diaphragm. Some time ago I had my valve cover off to replace the gasket. There s a catch tray of sorts below the metered diaphragm. Some rigs require this to be cleaned.

 

Is there another breather cap I can use in place of the oil fill cap? I also have a 91 2.5ltr...

 

Ok, so I thought I had the problem solved, but I drove it on the highway and pumped oil into my air box and filter.
Now I have installed a catch can that I ordered from Jeg's online. The CCV no longer has access to the air box.
I also noticed that as the oil breaks in, it seems to be slowing down the blow by in the engine.
Next I have to replace the air filter and run it up to 65-70 mph and see if the catch can has oil in it. At least it won't be in the air filter.

 

I am having the same issue. Tomorrow I am cleaning the CCV fitting in the front. Then I will change the oil and add Restore or something to condition the rings. valves. I will keep you posted

 

excessive blow by

The reason for the oil getting into the air filter is due to some kind of blow by, either by the rings or valves, That causes oil vapor under pressure in the valve cover. The air box is a negative pressure and pulls that air into the air box.

When it is excessive it starts to cause a problem in the air filter. Fix is to fix the cause of the blow by.

 

It's on the drivers side front side of valve cover. Brass fitting with a vac line attatched.

 

I had the same problem with a '93 and failed a smog check. I solved it by cleaning out the crankcase vent fitting which was clogged. I've read the increased pressure sends oil out of the CCV tube to the air filter.

I unscrewed the crankcase vent fitting and found the small pinpoint hole was totally blocked. I used a safety pin to remove all the gunk and haven't seen oil in my air filter since.

Hope that helps.

 

I had the same problem with a '93 and failed a smog check. I solved it by cleaning out the crankcase vent fitting which was clogged. I've read the increased pressure sends oil out of the CCV tube to the air filter.

I unscrewed the crankcase vent fitting and found the small pinpoint hole was totally blocked. I used a safety pin to remove all the gunk and haven't seen oil in my air filter since.

Hope that helps.

Where is this fitting? I have a '91 Wrangler which I'm positive has excessive blowby as my Air Filter is coated with engine oil. I only have tubing from my valve cover to my airbox and the tubing has NO REGULATION in it keeping oil from flowing from my valve cover to my airbox.

 

My YJ doesn't have a PCV valve. I found one that the books at schucks say, but it doesn't look the same. My ventilator is just a tube, no regulation. I had that problem, so I dropped the hose runnging from said connection to the airbox. Put one of those small little cone filters from schucks ($10) and put it right on that. Works fine.
Yesterday 03:51 PM

i also do not have a regulator of any kind, just tubing straight to the airbox.
would you mind posting a picture of what you did? i cant quite picture it.

 

My YJ doesn't have a PCV valve. I found one that the books at schucks say, but it doesn't look the same. My ventilator is just a tube, no regulation. I had that problem, so I dropped the hose runnging from said connection to the airbox. Put one of those small little cone filters from schucks ($10) and put it right on that. Works fine.

 

so i just figured out that 92 2.5l dont have a PCV. or at least, thats not the problem here.
it is behind my oil cap, the fresh air inlet, that is leaking the oil into my air filter.
i check the elbows and the tubing, there is nothing that is there to filter the oil out.
what should i do?

 

In your air cleaner there should be a breather element. It's a small square plastic piece that fits in the air cleaner and clips on the outside. There is a piece of material "element" that fits inside where it will collect vapors from the vent on the valve cover. Make sure it's not missing. If it's there, replace the element. I would also put in a new PCV. Both parts are inexpensive. You will always get some oil residue in your air cleaner due to the vapors venting into it. Check it once in awhile and remove your filter and wipe it out. After I do that I rotate the air filter.

 

I'm not sure about other Jeeps but the YJ PCV valve is right in front of the oil cap on the engine, Looks like this:

 

PCV Valve

The PCV Valve comes out of the top of the valve cover, it's L-shaped and fits in the palm of your hand. To take it out, you rotate it(clockwise, IIRC) and just pull it out. You should have 1 hose that runs from the valve to the air filter.

Now hopefully that was enough for you to find it. I would suggest before replacing it, shake it fairly hard. If you don't hear a rattle that might mean that the berring(spl?) inside is gummed up. I had this same problem and squirted about 1/4 a can of WD40 into it to clean it out, and that pretty much solved the problem. Just let it soak, pour the WD40 out and shake it up then keep repeating until it sounds pretty loose.

Hope this helps and saves you a couple bucks!