Like FormulaS340 said it may be the valve is bad, it's supposed to have a spring inside to act against the manifold vacuum so the valve doesn't just stay open all the time.
unless the pcv valve is missing parts it will only pass the same amount of air even if the spring is broken. the spring will close the valve at wide open throttle when the vacuum is very low but at idle there is enough vacuum to hold the pcv at max open. so even if you cant here it wiggle it wont effect the idle mixture unless parts are missing from it