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Home >> Chevrolet >> 2002 >> Prizm Base, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System & Component Testing >> Emission Systems & Sub-Systems >> Positive Crankcase Ventilation >> Checking PCV Valve Function
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Checking PCV Valve Function

NOTE: Engine must be sealed for PCV system to function as designed. If leakage, sludging or dilution of oil is noted and PCV system is functioning properly, check engine for cause and repair as necessary to ensure PCV system will continue to function properly.
  1. Disconnect PCV valve vacuum hose from cylinder head cover. Run engine at idle. Place thumb over end of PCV valve vacuum hose to check for vacuum. If vacuum does not exist, remove hose and check for obstruction. If PCV valve vacuum hose is okay, go to next step.
  2. Turn ignition off. Remove PCV valve. Visually inspect valve for varnish or deposits which may cause PCV valve operation to be sticky, restricted, or cause incomplete seating of valve. Shake valve and listen for rattle of check valve inside. If a clear rattle is not heard, replace PCV valve.