GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN-6628-A Locking Tool
    • EN-422 Installer

For equivalent regional tools, refer to Special Tools.

Removal Procedure

  1. Remove the camshaft adjuster. Refer to Camshaft Position Actuator Adjuster Replacement.
  2. Remove the rear timing belt cover. Refer to Timing Belt Rear Cover Replacement.
  3. Remove intake camshaft position sensor. Refer to Camshaft Position Sensor Replacement.
  4. Remove exhaust camshaft position sensor. Refer to Camshaft Position Sensor Replacement.
  5. Remove EN-6628-A locking tool .
  6. Counterhold at hexagon of camshaft.

    Note: Note removal sequence 1-4.


    Object Number: 2026542  Size: SH
  7. Remove the 4 camshaft bearing cap bolts.
  8. Note: Release the bearing support by striking it gently with a plastic hammer.

  9. Remove the first camshaft bearing cap.

  10. Object Number: 2027653  Size: SH
  11. Loosen the 8 exhaust camshaft bearing cap bolts working from outside to inside in a spiral in steps of 1/2 up to 1 turn.
  12. Remove the 8 exhaust camshaft bearing cap bolts.
  13. Note: Mark camshaft bearing caps before removal.

  14. Remove the 4 exhaust camshaft bearing caps Numbers 6-9 from the cylinder head.
  15. Remove the exhaust camshaft (1).

  16. Object Number: 2027651  Size: SH
  17. Loosen the 8 intake camshaft bearing cap bolts working from outside to inside in a spiral in steps of 1/2 up to 1 turn.
  18. Remove the 8 intake camshaft bearing cap bolts.
  19. Note: Mark camshaft bearing caps before removal.

  20. Remove the 4 intake camshaft bearing caps Numbers 2-5 from the cylinder head.
  21. Remove the intake camshaft (1).
  22. Note: Mark camshaft bearing caps before removal.

  23. Remove the intake camshaft (1).
  24. Detach the seal rings from the camshafts.

Installation Procedure

    Note: Coat with MoS 2 lubricating paste.


    Object Number: 2027632  Size: SH
  1. Install the intake camshaft.
  2. Note: Note the identification marking on the camshaft bearing cover.

  3. Install the 4 intake camshaft bearing cover Numbers 2-5.
  4. Caution: Refer to Fastener Caution in the Preface section.

  5. Install the 8 intake camshaft bearing cover bolts and tighten in a spiral from the inside to the outside to  8 N·m (71 lb in).
  6. Note: Coat with MoS 2 lubricating paste.


    Object Number: 2027633  Size: SH
  7. Install the exhaust camshaft.
  8. Note: Note the identification marking on the camshaft bearing cover.

  9. Install 4 the exhaust camshaft bearing cover No. 6-9
  10. Install the 8 exhaust camshaft bearing cover bolts and tighten in a spiral from the inside to the outside to  8 N·m (71 lb in).
  11. Note: Sealing surfaces must be free from oil and grease.

  12. Clean sealing surfaces of the first camshaft bearing support and the cylinder head with a suitable tool.
  13. Clean oil duct from any sealant residue.

    Note: 

       • It is essential to ensure that no sealant is applied outside the marked sealing areas.
       • The grooves adjacent to the sealing surfaces must remain free from sealant.

    Note: Sealing surfaces must be free from oil and grease.

  14. Apply surface sealant to sealing surfaces of the first camshaft bearing cap thinly and evenly.
  15. Check valve clearance and adjust if necessary. Refer to Valve Clearance Adjustment.
  16. Position the first camshaft bearing cap on the cylinder block and tighten the bolts approximately to  2 N·m (18 lb in).

  17. Object Number: 2027009  Size: SH

    Note: No sealant may reach the camshafts.

  18. Install the first camshaft bearing cap.
  19. Note: Note installation sequence 1-4.

  20. Install the first camshaft bearing cap bolts and tighten to  8 N·m (70 lb in).

  21. Object Number: 1945794  Size: SH
  22. Install 2 NEW sealing rings to the camshafts.
  23. Tighten the seal ring with EN-422 installer  (3) on the camshaft until this is in contact with the cylinder head.
  24. To install, use camshaft sprocket bolt (1) in conjunction with shims (2) with a total thickness of approximately 10 mm.
  25. Remove the EN-422 installer  (3).
  26. Turn the intake camshaft against the direction of engine rotation.
  27. Install EN-6628-A locking tool .
  28. Turn the exhaust camshaft in the direction of rotation of the engine.
  29. Install EN-6628-A locking tool .
  30. Install exhaust camshaft position sensor. Refer to Camshaft Position Sensor Replacement.
  31. Install intake camshaft position sensor. Refer to Camshaft Position Sensor Replacement.
  32. Install the rear timing belt cover. Refer to Timing Belt Rear Cover Replacement.
  33. Install the camshaft adjuster. Refer to Camshaft Position Actuator Adjuster Replacement.