GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN-845 Suction Device
    • EN-6361 Feeler Gauge

For equivalent regional tools, refer to Special Tools.


    Object Number: 1947354  Size: SH

    Note: Note the identification marking on the camshaft bearing caps.

  1. Install the exhaust camshaft.
  2. Lubricate the exhaust camshaft with MoS 2 lubricating paste. Refer to Adhesives, Fluids, Lubricants, and Sealers for the recommended lubricating paste.

    Caution: Refer to Fastener Caution in the Preface section.

  3. Tighten the camshaft bearing caps 1-4 in a spiral from the inside to the outside and tighten to  8 N·m (71 lb in).

  4. Object Number: 1947353  Size: SH
  5. Install the intake camshaft.
  6. Lubricate the exhaust camshaft with MoS 2 lubricating paste. Refer to Adhesives, Fluids, Lubricants, and Sealers for the recommended lubricating paste.

  7. Tighten the camshaft bearing caps 1-4 in a spiral from the inside to the outside and tighten to  8 N·m (71 lb in).

  8. Object Number: 2027009  Size: SH

    Note: 

       • Ensure no sealant reaches the camshafts.
       • Note the installation sequence 1-4.

  9. Install the first camshaft bearing cap and the 4 bolts and tighten to  8 N·m (71 lb in).
  10. When replacing the intake camshaft, inspect the valve lash of the intake valves.
  11. Inspect the 2 valve lash, intake valve cylinder 1.
  12. 7.1. Turn the intake camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 1 are in the test position.
    7.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  13. Inspect the 2 valve lash, intake valve cylinder 3.
  14. 8.1. Turn the intake camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 3 are in the test position.
    8.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  15. Inspect the 2 valve lash, intake valve cylinder 4.
  16. 9.1. Turn the intake camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 4 are in the test position.
    9.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  17. Inspect the 2 valve lash, intake valve cylinder 2.
  18. 10.1. Turn the intake camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 2 are in the test position.
    10.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  19. When replacing the exhaust camshaft, inspect the valve lash of the exhaust valves.
  20. Inspect the 2 valve lash, exhaust valve cylinder 4.
  21. 12.1. Turn the exhaust camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 4 are in the test position.
    12.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  22. Inspect the 2 valve lash, exhaust valve cylinder 2.
  23. 13.1. Turn the exhaust camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 2 are in the test position.
    13.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  24. Inspect the 2 valve lash, exhaust valve cylinder 1.
  25. 14.1. Turn the exhaust camshaft in the direction of engine rotation by the camshaft hexagon until the cams of cylinder 1 are in the test position.
    14.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.

  26. Inspect the 2 valve lash, exhaust valve cylinder 3.
  27. 15.1. Turn the exhaust camshaft in the direction of engine rotation by the camshaft hexagon gear until the cams of cylinder 3 are in the test position.
    15.2. Insert the EN-6361 gauge , inspect the valve lash.

    Write down the result.


    Object Number: 2026542  Size: SH

    Note: Note the removal sequence 1-4.

  28. Remove the 4 camshaft bearing support bolts.
  29. Release the bearing support by striking it gently with a plastic hammer.
  30. Remove the 1st camshaft bearing support (5).
  31. Note: Mark the exhaust camshaft bearing caps before removal.

  32. Detach the camshaft bearing caps 1-4 working from outside to inside in a spiral in steps of 1/2 up to 1 turn.
  33. Remove the camshaft bearing cover from the cylinder head.
  34. Remove the intake camshaft.
  35. Note: Mark the intake camshaft bearing caps before removal.

  36. Detach the camshaft bearing caps 1-4 working from outside to inside in a spiral in steps of 1/2 up to 1 turn.
  37. Remove the camshaft bearing cover from the cylinder head.
  38. Remove the exhaust camshaft.

  39. Object Number: 1937161  Size: SH
  40. Using the EN 845 device  (1), remove the 16 valve tappets.

  41. Object Number: 1937159  Size: SH
  42. Determine valve tappet size.
  43. 26.1. Measurement of the cup tappet installed 3.12 mm (0.123 in), identification number 12.
    26.2. Measured value between cams and cup tappets +0.31 mm (0.012 in) = 3.43 mm (0.135 in)
    26.3. Required value, valve lash - 0.25 mm (0.010 in)

            Note: The identification number, arrow, is on the inside of the valve tappet.

    26.4. Measurement of the new cup tappet = 3.18 mm (0.125 in), identification number 18.
    26.5. Use a valve tappet with this dimension or one that is nearest to it.