Positive Crankcase Ventilation: Inspection

With engine running at idle, remove PCV valve from rocker cover. A properly working valve makes a hissing noise as air passes through it. A strong vacuum should be felt immediately when a finger is placed over valve inlet.

Is the inspection result normal? 

YES: INSPECTION END

NO: Replace PCV valve.

Fig 1: Checking Positive Crankcase Ventilation Valve

Courtesy of NISSAN MOTOR CO., U.S.A.