Rear main still leaking!

[Stukboy]

I believe it's one of the two fittings on top of the valve cover. It allows air to escape from the engine into the air box. I may have used the wrong letters in naming it but I know it does clog and restrict the air thus pushing it out of the rear main seal. My terminology is limited but I know what I want to say.
The bottom line is if the air "stuff" on top of the valve cover gets blocked it can cause oil to shoot out of the rear main.
Stukboy

 

[Eagle]

PCV is a valve, the the 4.0L engine does NOT have one. What it has for a crankcase ventilation system is called CCV and it is the two tubes that come off the valve cover. The big one in front is intake, and the the small one at the rear is where air is supposed to be sucked out of the engine.

Yes, it clogs and can contribute to a leaking rear main seal, but it is not a PCV system with a PCV valve.

 

[ECKSJAY]

PCV is a valve, the the 4.0L engine does NOT have one. What it has for a crankcase ventilation system is called CCV and it is the two tubes that come off the valve cover. The big one in front is intake, and the the small one at the rear is where air is supposed to be sucked out of the engine.

Yes, it clogs and can contribute to a leaking rear main seal, but it is not a PCV system with a PCV valve.

Non-HO (87-90) 4.0L use a PCV valve cover. It's built in.

 

[cherokee89]

This has some good info:

http://www.off-road.com/jeep/cherokee/98/04_apr/valvecover/cover.html

 

[Rand McNally]

I have a 2001 XJ 4.0L with 56,000 miles that also appears to have a leaky rear main. The back of the oil pan is convered in oil and it is wet all along the bottom of the Jeep. It isn't enough to "drip" or puddle in the driveway, but it is enough to make everything wet. I don't want to go ripping into the rear seal if I don't have to. This doesn't seem like very many miles to be having seals go bad.

How common do the CCV's go bad?

 

[89xj]

for an 89, the haynes manual says to replace the ccv every 50,000 miles. i know for the renix, the dealer sells a replaced kit for it, not sure about 2001

look for oil on the air filter(blowby) and make sure all the ccv lines are not plugged and the grommets arnt cracked.

 

[JJacobs]

Non-HO (87-90) 4.0L use a PCV valve cover. It's built in.

PCV systems use a valve that often sticks. 4.0's have no such valve. They use a metered orifice to achieve the same effect. When the tubes plug up you get the same problem as a stuck pcv valve. However you cannot buy a pcv for a 4.0, they do not exist.

 

[BDbass]

I'm trying to find the source of an oil leak around the rear main area on my 2000 as well (about 60k). Today pulled both fittings out of the V/C (after reading about the CCV system here...). Mine were fine, darn it!
The deal w/ the CCV is- The front fitting is just open air intake from the air cleaner box. The rear fitting has a 'plug' inside of it w/ a small orifice (hole), and is the tube that 'vacuums' the crank case into the intake manifold. You want to make sure that orifice doesn't get plugged up, or you can get pressure build-up inside the crank case and push oil out.

 

[JJacobs]

The baffles inside the valve cover get gummed up and block the flow to the metered grommet sometimes, good to clean up the cover and pull the baffles once in a while

 

[BDbass]

FYI - After a much closer inspection, I've determined the source of my leak is the back of the oil pan itself. Better than the rear main, I suppose...