Missing hose from air box to valve cover

I just bought my '92 XJ and it is in 'ok' shape. I am starting to go through the engine compartment to see what kind of mickey mouse stuff has been don to it over the last 24 years. I noticed that the hose from the air box to the valve cover is missing, and the spot on the valve cover where it is supposed to connect has a rubber plug in it. But the port on the air box is just wide open. Should I just cap the port on the air box? Or should I buy the connection for the valve cover and the hose? TIA

Yeah that original part degrades and falls apart.
Should go from the pcv to the air box, I've replaced it several time over the years when doing the pcv.
Not sure if you can leave it as is or not, it may need to vent somehow. Usually this line is how oil blowback gets on the air filter.

the air box will grab unfiltered air is the result of it being unplugged on that side.

The other pcv on the valve cover should connect to the vacuum lines .



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but do I want oil blowback on the air filter?

XJonAZ said:

but do I want oil blowback on the air filter?

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Do you want dirt sucked into the crankcase?

The CCV will pull air from somewhere. Since the filtered air has been capped off, where do you suppose that CCV fresh air supply comes from?

XJonAZ said:

but do I want oil blowback on the air filter?

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Nobody does. But it's known issues with these jeeps.

I'm not sure if that valve needs to breath or not, but you could plug the opening on the air filter side and run a different type of breather filter with oil catch if you need to.

eBay has the mopar lines if you search crankcase breather. I don't think there is a aftermarket solution yet.







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Either replace it with a generic hose or use a small cone filter that you can attach to the PCV on the valve cover. The blow by is irritating but it's set up like that for emissions, so unless you're not in an emissions testing area, you should just go back to stock. On our jeeps, it's not that big of a deal and a quick pour of seafoam in your brake booster line every oil change will burn off all the blowby that got to your cylinders anyway.