GM Service Manual Online
For 1990-2009 cars only

Special Tools

    â€¢ EN 46108 Timing Chain Retention Tool
    â€¢ EN 46111 Crankshaft Rotation Socket

Removal Procedure

  1. Remove the lower intake manifold. Refer to Lower Intake Manifold Replacement.
  2. Remove the camshaft cover. Refer to Camshaft Cover Replacement - Right Side.
  3. Remove the camshaft sensors. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake.
  4. Remove the intake camshaft position actuator solenoid. Refer to Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake.
  5. Remove the crankshaft balancer. Refer to Crankshaft Balancer Replacement.

  6. Object Number: 1306310  Size: SH
  7. Rotate the crankshaft with the EN 46111 until the camshafts are in a neutral (low tension) position. The camshaft flats will be parallel with the camshaft cover rail (1).
  8. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1340931  Size: SH

    Note: 

       â€¢ Use an open-end wrench at the camshaft hex to prevent camshaft/engine rotation.
       â€¢ DO NOT remove the camshaft position actuator bolt at this time.

  9. Loosen the camshaft position actuator bolt.

  10. Object Number: 1341287  Size: SH

    Note: Ensure that the tips of the EN 46108 are fully engaged into the timing chain (3 and 4).

  11. Install the EN 46108 (1 and 2) in order to retain the timing chain.
  12. Firmly tighten the EN 46108 nuts.


    Object Number: 1306457  Size: SH

    Note: Ensure that the camshaft timing chain and the camshaft position actuators are marked for proper assembly.

  13. Mark the timing chain and the respective locations on camshaft position actuators (15-18).
  14. Remove the camshaft position actuator bolt.
  15. Remove the camshaft bearing caps and the camshaft. Refer to Camshaft Removal - Right Side.

Installation Procedure


    Object Number: 1306457  Size: SH

    Note: 

       â€¢ Ensure that the marks on the camshaft position actuators and the timing chain (15-18) are aligned.
       â€¢ DO NOT tighten the camshaft position actuator bolt at this time.

  1. Locate the camshafts to the cylinder head and assemble the camshaft actuators to the camshafts.
  2. Install the camshafts and the camshaft bearing caps. Refer to Camshaft Installation - Right Side.
  3. Remove the EN 46108 .
  4. Install the crankshaft balancer. Refer to Crankshaft Balancer Replacement.
  5. Caution: Refer to Torque Reaction Against Timing Drive Chain Caution in the Preface section.


    Object Number: 1340931  Size: SH

    Note: Use an open-end wrench at the camshaft hex to prevent camshaft/engine rotation.

  6. Install and tighten the camshaft position actuators. Refer to Camshaft Position Actuator Installation - Right Side Intake and Camshaft Position Actuator Installation - Right Side Exhaust.
  7. Install the intake camshaft position actuator solenoid. Refer to Camshaft Position Actuator Solenoid Valve Solenoid Replacement - Bank 1 (Right Side) Intake.
  8. Install the camshaft sensors. Refer to Camshaft Position Sensor Replacement - Bank 1 (Right Side) Exhaust and Camshaft Position Sensor Replacement - Bank 1 (Right Side) Intake.
  9. Install the camshaft cover. Refer to Camshaft Cover Replacement - Right Side.
  10. Install the lower intake manifold. Refer to Lower Intake Manifold Replacement.