GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 23788 Hand Operated Vacuum Pump

The waste-gate actuator assembly can be replaced separately from the turbocharger assembly. In order to check the operation of the waste-gate actuator, perform the following steps.

  1. With the engine off, inspect the actuator rod and lever. The actuator rod and lever should move back and forth without any tension.
  2. Apply 5 inches of HG vacuum to the actuator. The actuator rod and lever should close the waste-gate. Look for the rod to move toward the front of the engine.

If the rod does not snap back to a closed position, the waste-gate actuator is defective. Replace the waste-gate actuator. Refer to Waste-Gate Actuator.