What would cause this

99xj front valve cover breather isn't sucking in air and is spitting out moisture, what would cause this, thanks

The back valve cover breather is clogged, so intake manifold isn't sucking from it, thus excess pressure is blown into the front one.

I blew out back breather and tude and still not sucking in

If the CCCV (jeep's flavor of the PCV) tube is not plugged, and it's blowing gunk out the front tube then the engine has extra blow-by.
A compression test and cylinder leak-down test is in order to find the cause.

dirtyjerseyjeep said:

99xj front valve cover breather isn't sucking in air and is spitting out moisture, what would cause this, thanks

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Where is it "spitting moisture" from? What do you mean by "moisture"?

How is your idle RPM? High? Low?

The CCV fitting orifice (rear of VC) is a metered orifice, approximately .106" in diameter. If this orifiice size is reduced (clogged) you will have lower RPM than normal. Proof is to disconnect the CCV tube at the intake manifold, start the engine, note that the RPM is high, gradually slide your thumb over the intake manifold CCV vacuum fitting at note how the RPM decreases up to the point where you completely cover the vacuum fitting and the engine will die.

Did you observe the oil fill hole in the VC with the engine running? Are there vapors blowing out? Is this where the "moisture" is "spitting" out?

What's it look like inside of the VC (as viewed through the oil fill hole)? Does it look like you have sludge build-up?

Engine rpms are normal when I disconnect rear tube at intake rpms jump, by moisture I mean it's a light creamy liquid that's dripping out of the front tubed where it hooks up to intake box

dirtyjerseyjeep said:

Engine rpms are normal when I disconnect rear tube at intake rpms jump, by moisture I mean it's a light creamy liquid that's dripping out of the front tubed where it hooks up to intake box

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Pull your valve cover and see what's going on under there. A light creamy liquid sounds like anti-freeze mixed with oil.

I know you don't like answering all the questions put to you on this thread but... Do you have a creamy colored oil on your dipstick? Does it look like there's oil in the anti-freeze overflow reservoir?

Sidewinder CC said:

Pull your valve cover and see what's going on under there. A light creamy liquid sounds like anti-freeze mixed with oil.

I know you don't like answering all the questions put to you on this thread but... Do you have a creamy colored oil on your dipstick? Does it look like there's oil in the anti-freeze overflow reservoir?

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Condensation is also a normal by-product of engine combustion, and the heat-cooling cycle.

continuous short trips with out a good warm up will cause condensation to form in the valve cover and breather tube in the form a of a milky ooze. more so in the winter months and, If the cccv is not working properly, it will add to the problem.

Do you do "cold start, short runs"?

If so, your oil will not heat up enough to evaporate the condensation in your crankcase--which is normal--and you will find "latte" under the oil filler cap, sometimes at the upper section of the dipstick.

The oil cap never has this milky consistencey not does the dipstick I just want to front breather to suck in as it should.

dirtyjerseyjeep said:

I just want to front breather to suck in as it should.

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:roflmao:

When you cleaned the back tube did you clean the fitting on the manifold? Just takes a second to poke a stiff wire or small rod into it to dislodge any carbon build up. You will feel it if it is clogged.

Again....

What's it look like inside of the VC (as viewed through the oil fill hole)? Does it look like you have sludge build-up?