PCV holds closed on high idle vacuum, opens on the crack of the throttle and closes again on low manifold vacuum WOT. The shuttle valve you hear rattling around is suspended in mid stroke by these 2 springs. It can still be bad even if it rattles. You can extend the PCV line up to the air cleaner through a oil catch can, just a can with the in and out hoses up top like a shop vac. The oil is heavier than air so it'll settle at the bottom. Drain at your neede interval but it should not catch much oil at all if the $4 PCV valve is good.
