GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 42492-A (KM-421-A) Timing Belt Adjuster
    • J 45059 Angle Meter
    • KM-470-B Angular Torque Gage

Removal Procedure


    Object Number: 1291147  Size: SH
  1. Remove the fuel pump fuse.
  2. Start the engine. After it stalls, crank the engine for 10 seconds to rid the fuel system of fuel pressure.
  3. Caution: Refer to Battery Disconnect Caution in the Preface section.

  4. Disconnect the negative battery cable.
  5. Disconnect the electronic control module (ECM) ground terminal from the intake manifold.
  6. Drain the engine coolant. Refer to Cooling System Draining and Filling .

  7. Object Number: 1291219  Size: SH
  8. Drain the engine oil.
  9. Remove the air cleaner housing.

  10. Object Number: 1291220  Size: SH
  11. Remove the throttle cable and inlet/outlet coolant hoses.

  12. Object Number: 1291222  Size: SH
  13. Remove the thermostat upper hose.

  14. Object Number: 1291224  Size: SH
  15. Remove the intake manifold pressure sensor, intake air temperature sensor and coolant temperature sensor.
  16. Remove the intake manifold support bracket.

  17. Object Number: 1291225  Size: SH
  18. Remove the all the vacuum hoses from the intake manifold including brake booster vacuum hose.
  19. Remove the ignition cables from the spark plugs.
  20. Remove the direct ignition coil and the bracket from the cylinder head.

  21. Object Number: 1291226  Size: SH
  22. Remove the serpentine accessory drive belt. Refer to Power Steering Pump Belt Replacement .
  23. Remove the front passenger side tire. Refer to Tire and Wheel Removal and Installation .
  24. Remove the front wheel housing shield.

  25. Object Number: 1291228  Size: SH
  26. Remove the upper front timing belt cover bolts.
  27. Remove the upper front timing belt cover.
  28. Align the camshaft gear timing marks.
  29. Remove the crank shaft pulley.
  30. Remove the lower front timing belt cover bolts and cover.

  31. Object Number: 1291229  Size: SH
  32. Slightly loosen the water pump retaining bolts.
  33. Rotate the water pump counterclockwise using J 42492-A to relieve the timing belt tension.
  34. Remove the timing belt. Refer to Timing Belt Replacement .

  35. Object Number: 1291231  Size: SH
  36. Remove the engine mounting bracket. Refer to Engine Mount Replacement .
  37. Remove the camshaft cover. Refer to Valve Rocker Arm Cover Replacement .

  38. Object Number: 1291233  Size: SH
  39. While holding the intake camshaft firmly in place, remove the intake camshaft gear bolt and gear.
  40. Important: Take extreme care to prevent any scratches, nicks or damage to the camshafts.

  41. While holding the exhaust camshaft firmly in place, remove the exhaust camshaft gear bolt and gear.

  42. Object Number: 1291234  Size: SH
  43. Remove the timing belt automatic tensioner.
  44. Remove the timing belt idler pulley.
  45. Remove the right engine mount. Refer to Engine Mount Replacement .
  46. Remove the rear timing belt cover.

  47. Object Number: 1291236  Size: SH
  48. Remove the intake and exhaust manifold. Refer to Intake Manifold Replacement and Exhaust Manifold Removal .
  49. Remove the cylinder head bolts gradually in the sequence shown and remove the cylinder head.
  50. Notice: Use extreme care when removing the cylinder head to prevent any engine oil , dirt, or coolant from entering the engine. Damage to the engine could result.

  51. Remove the cylinder head gasket.
  52. Clean the gasket surfaces on the cylinder head and the engine block. Refer to Cylinder Head Cleaning and Inspection .

Installation Procedure


    Object Number: 1291240  Size: SH
  1. Install the new cylinder head gasket.
  2. Install the intake/exhaust manifold to the cylinder head. Refer to Intake Manifold Replacement and Exhaust Manifold Removal .
  3. Notice: Refer to Fastener Notice in the Preface section.

  4. Install the cylinder head bolts gradually in the sequence shown using J 45059 or KM-470-B .
  5. Tighten
    Tighten the cylinder head bolts to 25 N·m (18 lb ft) and retighten the cylinder head bolts 70 degrees plus 70 degrees plus 50 degrees.

  6. Install the right engine mount. Refer to Engine Mount Replacement .

  7. Object Number: 1291224  Size: SH
  8. Connect the throttle cable at the throttle body and the intake manifold.
  9. Install the intake manifold support bracket upper bolts to the intake manifold.
  10. Tighten
    Tighten the intake manifold support bracket upper bolts to the intake manifold to 25 N·m (18 lb ft).

  11. Connect the surge tank coolant hose at the throttle body.
  12. Connect the heater inlet hose to the cylinder head.

  13. Object Number: 1291241  Size: SH
  14. Install the generator upper retaining bolt.
  15. Tighten
    Tighten the generator upper retaining bolt to 20 N·m (15 lb ft).

  16. Connect the fuel feed line at the fuel rail.
  17. Connect all the disconnected vacuum hoses and the brake booster vacuum hose at the intake manifold.

  18. Object Number: 1291211  Size: SH
  19. Install the catalytic converter retaining nuts at the exhaust manifold flange.
  20. Tighten
    Tighten the catalytic converter to exhaust manifold flange nuts to 40 N·m (30 lb ft).


    Object Number: 1291234  Size: SH
  21. Install the rear timing belt cover.
  22. Install the rear timing belt cover bolts.
  23. Tighten
    Tighten the rear timing belt cover bolts to 10 N·m (89 lb in).


    Object Number: 1291243  Size: SH
  24. Install the timing belt automatic tensioner.
  25. Tighten
    Tighten the timing belt automatic tensioner bolts to 25 N·m (18 lb ft).

  26. Install the timing belt idler pulley.
  27. Tighten
    Tighten the timing belt idler pulley bolt to 25 N·m (18 lb ft).


    Object Number: 1291233  Size: SH

    Important: Take extreme care to prevent any scratches, nicks or damage to the camshafts.

  28. Install the intake and exhaust camshaft gear.
  29. Tighten
    Tighten the intake and exhaust camshaft gear bolts to 67.5 N·m (49 lb ft).


    Object Number: 1291244  Size: SH
  30. Apply a small amount of gasket sealant to the corners of the front camshaft caps and the top of the rear camshaft cover-to-cylinder head seal.
  31. Install the camshaft cover and the gasket. Refer to Valve Rocker Arm Cover Replacement .

  32. Object Number: 1291245  Size: SH
  33. Connect the ignition wires to the spark plugs.
  34. Install the oil filler cap.
  35. Connect the engine ventilation hose to the camshaft cover.
  36. Align the timing marks on the camshaft gears.
  37. Align the mark on the crank shaft gear with the notch at the bottom of the rear timing belt cover.

  38. Object Number: 1291246  Size: SH
  39. Install the timing belt.
  40. Rotate the water pump clockwise using the J 42492-A to apply tension to the timing belt.
  41. Tighten
    Tighten the water pump retaining bolts to 10 N·m (89 lb in).

  42. Check and adjust the timing belt tension. Refer to Timing Belt Inspection .

  43. Object Number: 1291248  Size: SH
  44. Install the upper and lower front timing belt covers.
  45. Tighten
    Tighten the upper and lower front timing belt cover bolts to 10 N·m (89 lb in).

  46. Install the crank shaft pulley bolt.
  47. Tighten
    Tighten the crank shaft pulley bolt to 95 N·m (70 lb ft) and retighten 30 degrees plus 15 degrees.

  48. Install the serpentine accessory drive belt. Refer to Power Steering Pump Belt Replacement .
  49. Connect the upper radiator hose to the thermostat housing.
  50. Install the front wheel and splash shield. Refer to Tire and Wheel Removal and Installation .

  51. Object Number: 1291151  Size: SH
  52. Install the air cleaner housing.
  53. Tighten
    Tighten the air cleaner housing bolts to 10 N·m (89 lb in).

  54. Connect the breather tube to the cam shaft cover.
  55. Install the crank shaft pulley bolt.
  56. Connect the IAT sensor connector.
  57. Connect the intake manifold pressure sensor, intake air temperature sensor and coolant temperature sensor connector.

  58. Object Number: 1291249  Size: SH
  59. Connect the direct ignition coil connector.
  60. Connect the fuel injector harness connectors.
  61. Connect the oxygen sensor connector and the ECM ground terminal at the intake manifold.
  62. Install the fuel pump fuse.
  63. Connect the negative battery ground cable.
  64. Refill the engine cooling system. Refer to Cooling System Draining and Filling .