Positive Crankcase Ventilation (PCV)

With engine idling, disconnect ventilation hose from PCV valve. If hissing noise and strong vacuum are not present at hose end, check hose and hose connections for leaks and obstructions. Repair or replace as necessary. Connect hose to PCV valve. Remove PCV valve from intake manifold. Place finger over PCV valve. Vacuum should be present. Remove finger from PCV valve. Valve should snap back.