Jeep YJ 2.5l frech air intake blowing off

[gsaade]

Hello,

I was wondering if someone can help diagnose a problem. I have an 88 YJ with a 2.5L engine with a carb setup. My fresh air valve that works with the PCV blows off every week and throws oil everywhere in the engine compartment. What can cause this problem? do I need a PCV and fresh air valve setup? it looks like it is pretty loose, what happens if you glue it in place?

Attached is a pic to show the part of the engine I am talking about.

Thanks for the help!

 

[JPNinPA]

This is an oil breather. If you start the engine with this removed there should be a suction at this hole. If there is pressure you likely have a an issue. Either blow by from bad rings or valves not seating.

Ps - It looks like your missing the hose from the breather to the intake

 

[Bounty__Hunter]

Too much crankcase pressure, either from blow-by (as mentioned above) or from the vacuum source not properly routed to the valve cover.

The line from the carb to the front of the valve cover should suck crankcase fumes into the intake to be burnt. This causes the valve your referencing at the back of the valve cover to suck air into the valve cover.

The early 2.5L engines are notorious for excessive blowby causing excessive crankcase pressure, especially above 2k RPM's.

 

[JPNinPA]

Bounty has it correct. Pcv valve to intake and rear breather to where you have the PCv valve connected on the air filter.

Make sure your PCv is clean and operating correctly.

 

[gsaade]

thank you for the help! i will check compressions again, but 2 weeks ago i had 120 on all 4.

 

[JPNinPA]

Could it be as simple as worn components and oil buildup?

Change the connections as noted.

Pull the part and feel if there is suction or pressure in the valve cover. Only then would I check cylinder pressure.