GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • EN 46330 Timing Belt Tensioner Retaining Pin
    • EN 46331 Timing Belt Tensioner Pulley Retaining Bolt
    • EN 46337 Camshaft Sprocket/Crankshaft Balancer Holder

    Object Number: 897052  Size: SH

    Important: The powertrain control module (PCM) must perform the idle learn procedure to determine the minimum throttle position and to establish idle speed when any of the following components are replaced:

       • Throttle body
       • Timing belt
       • Timing belt drive sprocket
       • Crankshaft and bearings
    Refer to Idle Learn .

  1. Clean the belt sprockets and covers.
  2. Rotate the crankshaft and align the top dead center (TDC) mark (2) on the sprocket (237) with the pointer on the oil pump housing (1).

  3. Object Number: 897065  Size: SH
  4. Rotate the left camshaft sprocket to TDC by aligning the mark (2) on the sprocket with the pointer (1) on the cover.

  5. Object Number: 897064  Size: SH
  6. Rotate the right camshaft sprocket to TDC by aligning the mark (2) on the sprocket with the pointer (1) on the cover.

  7. Object Number: 1308172  Size: SH
  8. Install the EN 46331 . Screw the EN 46331 all the way in by hand, until the tool contacts the timing belt tensioner. Tighten until snug.

  9. Object Number: 897044  Size: SH
  10. Install the belt (235) onto the sprockets. Install the timing belt in a clockwise sequence starting with the tensioner pulley. Refer to Camshaft Timing Belt Alignment Diagram .
  11. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 897043  Size: SH
  12. Tighten the idler pulley bolt (238).
  13. Tighten
    Tighten the bolt to 44 N·m (33 lb ft).


    Object Number: 897057  Size: SH
  14. Remove the EN 46330 .

  15. Object Number: 1308173  Size: SH
  16. Remove the EN 46331 .

  17. Object Number: 1352579  Size: SH
  18. Install the guide (236), balancer (228), and bolt (227). Tighten the bolt until snug.

  19. Object Number: 1352580  Size: SH
  20. Using the EN 46337 , rotate the crankshaft clockwise about 5 or 6 complete revolutions to position the timing belt on the sprockets.

  21. Object Number: 897052  Size: SH
  22. Align the mark (2) on the sprocket with the pointer (1) on the oil pump housing.

  23. Object Number: 897065  Size: SH
  24. Inspect the left camshaft sprocket for proper alignment. The TDC mark (2) on the sprocket should align with the pointer (1) on the cover.

  25. Object Number: 897064  Size: SH
  26. Inspect the right camshaft sprocket for proper alignment. The TDC mark (2) on the sprocket should align with the pointer (1) on the cover.

  27. Object Number: 1352579  Size: SH
  28. Remove the bolt (227), balancer (228) and guide (236).