The PCV is probably on the opposite valve cover. All that would happen with this doohicky being disconnected is that air would flow through the oil fill hole, through the engine, and into the PCV, which is pretty much what normally happens. The PCV valve will prevent the manifold vacuum from becoming depleted, regardless of whether the crankcase is open or closed.



If a lot of oil splashed out of that hole, you may have been running the engine low on oil. Dirt could have gotten in here, but would probably be cleansed through the oil filter. Other than that, there's no way this would cause long term harm. Your emissions problem is something else. Possibly the PCV valve itself is defective, and that's why your fill hose blew off. I'd start by replacing the valve.