No PCV valve / small oil leak

[Adodero]

Hey folks,

I just got a 1979 CJ7 with the AMC 258 i6 / 4.2l a few days ago and there is some oil spilling out of the oil filler cap at a slow pace (we also replaced the filler cap). After doing some reading, it seems the PCV valve may be the culprit, especially since we don't have one.

I'm still trying to figure out what the PO did, it seems he disconnected most of the vacuum lines from the carb (vacuum advance was off even). The bit I can't figure out (I'm a n00b) is what is over the PCV valve and what I should do about it. Could this setup be what is causing the oil to come out?

Right now we have the stock carter carb...

Picture below. Thanks!

 

[gert]

You do need a PCV valve, it looks like you have one on the back of your valve cover, if it is not then you need to get one and attach it to the bottom of the carb

 

[harleydragon]

I see that you do have a pcv valve but can't tell if the other end of the hose is attached..Once you make sure it is attached to the bottom of the carb or to the intake manifold,with the engine running,pull the pcv out of the valve cover and make sure it has a good vacuum. You can slide your thumb over the end to check this.If it has a good vacuum then check inside where it plugs into the valve cover and make sure it is not cruded up,preventing flow.If it does not have a good vacuum then pull the hose off the other end,at the carb/manifold and see if you have vacuum at that point..If you do,then replace the pcv and either clean or replace the hose..If you don't have vacuum at the carb/manifold then it may be cruded up inside..I usually take a thin bladed screw driver or a welding rod and clear that passage..once you get the pcv working then it will pull air in those passages where your leak was and probably stop it

 

[Adodero]

Thanks for the info. I'll try to pull the valve that is there and see if it's working.

The valve towards the back of the cover does run to the carb, but I thought the AMC 258 i6 / 4.2l had two? One towards the back and the other up front.

What is that silver cap on the front?

 

[harleydragon]

that silver cap is a vent..someone has installed it in place of the original hose that connected to the breather on the carb..what you have will work fine..the back hose with the pcv valve should connect to the bottom of the carb or intake manifold..look and you should find the place that it connects