project_renix

so I will start with the issue im having...

My airbox is filling with oil, because the fresh air tube is not sucking in fresh air. Instead, it's blowing out crank case pressure.

I tried fixing it by upping the size of the vacuum line from the back of the valve cover to the intake, thinking that maybe it wasn't drawing out the crank case pressure enough, but that didn't work.

So my question is, what could it be? The compression is good cuz when I kill the ignition the engine stops immediately. It doesn't stop like it has low compression. Is there something im overlooking? Am I assuming wrong with the rings?

investinwaffles

Did you change the actual CCV valves out? The plastic piece that sits on the valve cover.

project_renix

Yes. I changed out both fittings, and got a bigger vacuum nozzle for the bigger line on the back of the valve cover to the intake manifold.

scottmphoto

Did you do the mod on the back fitting on the inside of the VC. The write-up is on here.

Batman33165

What year is the jeep?

project_renix

The jeep is an 87 with a 4.0

Batman33165

Ok u can do 2 things... change the valve cover to a newer model of jeep anything after 91 but look only for metal... a friend told me some are metal others are made of different material...

Or u can look up cruiser 54's write up... he basically cuts the inside of the valve cover ccvs about an inch or 2... and then drills one hole on each towards the back of the valve cover....

Supposedly its supposed to stop the oil pick up

Pelican

If you have not already done so, check the fitting in the manifold that the rear hose attaches to. Just use a stiff piece of wire or whatever to make sure it is clear. I had oil in the airbox until I discovered the fitting was clogged.

freegdr

Valve cover fix.......https://www.cherokeeforum.com/f2/ren...132440/index3/

cruiser54

Make sure both the orifice in the rear of the valve cover is clear AND the hole in the fitting at the other end of that hose in the manifold. Grommets need to be in good condition so they seal.

Post 25 in my link shows exactly how to do the valve cover mod, with photos.