Can some one tell me the part name for the 90 degree elbow fitting , that is the forward most fitting on the valve cover, that routes to the air cleaner box, and, how does it attach? Rubber grommet? Force fit plastic? Twist fit? Mine is broken and is just resting in the hole by the force if gravity, allowing oil to blow out and dirt to go in. Part numbers would be appreciated.



And secondly what is and where should the tube be routed from the most rearward valve cover fitting? Mine is just snipped off, again allowing oil and oil vapor to spew about the engine compartment, causing a big visual mess and a stinky odor.

See photo

Dorman part number 46005 is the rear grommet with the correct tube that goes to the intake manifold, so the vacuum can draw the fumes through the intake. The tube has a small hole/orifice on the end that plugs into the grommet.

The front fitting comes as part of the vacuum harness 46003. The original rubber gets hard and crumbles. I don't think you can get just the fitting. 46004 is the other half of the vacuum harness.

Should the front vent tube have a one-way valve in it? The original is long-gone on my 1990 XJ.
As an experiment, I tried blocking it off and my engine didn't like that. It started bubbling oil out of the dip stick.

No.

Nope, one valve in the front. Sounds like you have some blow-by if plugging that caused pressure at the dipstick.

I'm sure this engine has plenty of compression loss from both ends. It has over 325,000 miles and the odometer is currently broke. But also in the course of learning from this thread, I checked out the PCV tube which was totally plugged with gunk. So I replaced that, and now it runs that much better. A ton of gunk flew out the tailpipe after I replaced the fuel injectors and poured in a can of Sea Foam.
My goal is to pass California smog test soon.

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