Positive Crankcase Ventilation (PCV) Valve: Inspection

Remove the positive crankcase ventilation valve.
Insert a thin stick into the positive crankcase ventilation valve from the threaded side to check that the plunger moves.
If the plunger does not move, the positive crankcase ventilation valve is clogged. Clean or replace it.

Fig 1: Checking PCV Valve Plunger Movement
Courtesy of HYUNDAI MOTOR CO.