GM Service Manual Online
For 1990-2009 cars only

Tools Required

EN 46328 Camshaft Holding Tool


    Object Number: 928335  Size: SH
  1. Install the right secondary camshaft drive chain guide.
  2. Loosely install the lower right secondary camshaft drive chain guide bolt.

  3. Object Number: 928332  Size: SH
  4. Install the right secondary camshaft drive chain shoe.
  5. Notice: Refer to Fastener Notice in the Preface section.

  6. Install the right secondary camshaft drive chain shoe bolt.
  7. Tighten
    Tighten the right secondary camshaft drive chain shoe bolt to 25 N·m (18 lb ft).


    Object Number: 928328  Size: SH
  8. Install the right secondary camshaft drive chain by sliding the chain down through the right cylinder head and placing the chain on the end of the camshafts.
  9. Route the right secondary camshaft drive chain around the outer row of the intermediate drive chain sprocket teeth.

  10. Object Number: 928325  Size: SH
  11. Install the right intake and exhaust camshaft position actuators into the right secondary camshaft drive chain.

  12. Object Number: 948044  Size: SH
  13. Install the right intake and exhaust camshafts onto the camshafts. The camshaft sprocket notch marked "RI" which indicates right intake, engages the intake camshaft pin and the camshaft sprocket notch marked "RE" which indicates right exhaust, engages the exhaust camshaft pin.

  14. Object Number: 928323  Size: SH
  15. If necessary, use an open wrench on the hex cast near the front of each camshaft to help align the sprocket notch to the camshaft pin.
  16. Loosely install the right intake and exhaust camshaft position actuator oil control valves.

  17. Object Number: 948062  Size: SH
  18. Ensure the perpendicular alignment of the right intake and exhaust camshaft sprocket notches and camshaft pins to the cylinder head.

  19. Object Number: 928316  Size: SH
  20. Install the EN 46328 to the right cylinder head camshafts.

  21. Object Number: 685331  Size: SH
  22. Install the upper right secondary camshaft drive chain guide bolt.
  23. Tighten
    Tighten BOTH the upper and lower right secondary camshaft drive chain guide bolts to 25 N·m (18 lb ft).


    Object Number: 53004  Size: SH
  24. Collapse the right secondary camshaft drive chain tensioner using the following procedure:
  25. 14.1. Rotate the ratchet release lever counter-clockwise and hold.
    14.2. Collapse the right secondary camshaft drive chain tensioner shoe and hold.
    14.3. Release the ratchet lever and slowly release the pressure on the shoe.
  26. When the ratchet lever moves to the first detent a click should be heard and felt. Insert a pin through the hole in the release lever in order to lock the right secondary camshaft drive chain tensioner shoe in the collapsed position.

  27. Object Number: 928320  Size: SH

    Important: Ensure the right secondary camshaft drive chain tensioner release lever is facing out.

  28. Install the right secondary camshaft drive chain tensioner.
  29. Install the right secondary camshaft drive chain tensioner bolts.
  30. Tighten
    Tighten the right secondary camshaft drive chain tensioner bolts to 25 N·m (18 lb ft).

  31. Remove pin from right secondary camshaft drive chain tensioner lever.

  32. Object Number: 948075  Size: SH
  33. Ensure the correct alignment of all secondary timing components.

  34. Object Number: 517185  Size: SH
  35. Ensure the correct alignment of all primary timing components (1, 2).
  36. Notice: Refer to Torque Reaction Against Timing Drive Chain Notice in the Preface section.


    Object Number: 1275675  Size: SH
  37. Use an open end wrench on the hex cast into the left intake camshaft, in order to prevent the camshaft from rotating, when tightening the camshaft position actuator oil control valve on the left intake camshaft.
  38. Tighten the camshaft position actuator oil control valve on the left intake camshaft.
  39. Tighten
    Tighten the camshaft position actuator oil control valve to 120 N·m (89 lb ft).


    Object Number: 1275674  Size: SH
  40. Use an open end wrench on the hex cast into the left exhaust camshaft, in order to prevent the camshaft from rotating, when tightening the camshaft position oil actuator control valve on the left exhaust camshaft.
  41. Tighten the camshaft position oil actuator control valve on the left exhaust camshaft.
  42. Tighten
    Tighten the camshaft position actuator oil control valve to 120 N·m (89 lb ft).


    Object Number: 1275677  Size: SH
  43. Use an open end wrench on the hex cast into the right intake camshaft, in order to prevent the camshaft from rotating, when tightening the camshaft position actuator oil control valve on the right intake camshaft.
  44. Tighten the camshaft position actuator oil control valve on the right intake camshaft.
  45. Tighten
    Tighten the camshaft position actuator oil control valve to 120 N·m (89 lb ft).


    Object Number: 1275678  Size: SH
  46. Use an open end wrench on the hex cast into the right exhaust camshaft, in order to prevent the camshaft from rotating, when tightening the camshaft position actuator oil control valve on the right exhaust camshaft.
  47. Tighten the camshaft position actuator oil control valve on the right exhaust camshaft.
  48. Tighten
    Tighten the camshaft position actuator oil control valve to 120 N·m (89 lb ft).