GM Service Manual Online
For 1990-2009 cars only

    Object Number: 607625  Size: SH

    Caution: Do not breathe the air through the EVAP component tubes or hoses. The fuel vapors inside the EVAP components may cause personal injury.

  1. Blow air into the cylinder head side of the PCV valve.
  2. Check that air passes through the PCV valve easily.

  3. Object Number: 607623  Size: SH
  4. Blow air into the intake manifold side of the PCV valve.
  5. Check that air passes through the PCV valve with high resistances.
  6. If the PCV valve fails either test, replace the PCV valve.