GM Service Manual Online
For 1990-2009 cars only

Tools Required

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

Removal Procedure

    Caution: Refer to Safety Glasses Caution in the Preface section.


    Object Number: 1241528  Size: SH

    Caution: Valve springs can be tightly compressed. Use care when removing the retainers and plugs. Personal injury could result.

  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 engine control module (ECM) ground terminal from the intake manifold.

  6. Object Number: 1241530  Size: SH
  7. Drain the engine coolant. Refer to Cooling System Draining and Filling .
  8. Disconnect the intake air temperature (IAT) sensor connector.
  9. Disconnect the breather tube from the valve cover.
  10. Disconnect the air intake tube from the throttle body.

  11. Object Number: 1241531  Size: SH
  12. Disconnect the electronic ignition (EI) system ignition coil connector.
  13. Disconnect the engine coolant temperature (ECT) sensor connector. Refer to Engine Coolant Temperature Sensor Replacement .

  14. Object Number: 1241532  Size: SH
  15. Disconnect the idle air control (IAC) valve connector.
  16. Disconnect the throttle position (TP) sensor connector.

  17. Object Number: 1241533  Size: SH
  18. Remove the camshaft position (CMP) sensor.

  19. Object Number: 1241535  Size: SH
  20. Remove the air cleaner housing bolts.
  21. Remove the air cleaner housing.

  22. Object Number: 1241546  Size: SH
  23. Remove the upper timing belt cover bolts.
  24. Remove the upper timing belt cover.

  25. Object Number: 1241548  Size: SH
  26. Align the camshaft gear timing mark to the notch in the rear timing belt cover.

  27. Object Number: 1241549  Size: SH
  28. Remove the right front wheel. Refer to Tire and Wheel Removal and Installation .
  29. Remove the right front wheel well splash shield.
  30. Notice: Refer to Belt Dressing Notice in the Preface section.

  31. Remove the serpentine accessory drive belt.

  32. Object Number: 1241550  Size: SH
  33. Disconnect the fuel feed line at the fuel rail.

  34. Object Number: 1241551  Size: SH
  35. Remove the power steering pipe bracket mounting nut. Refer to Power Steering Pump Hoses and Pipes Replacement .
  36. Remove the alternator nut.
  37. Remove the alternator bracket retaining nut.
  38. Remove the alternator bracket.

  39. Object Number: 1241555  Size: SH
  40. Disconnect the brake booster vacuum hose at the intake manifold.
  41. Disconnect all of the necessary vacuum hoses and electrical connector.
  42. Disconnect the manifold absolute pressure (MAP) sensor from the intake manifold.

  43. Object Number: 1241552  Size: SH
  44. Remove the crankshaft pulley bolt.
  45. Remove the crankshaft pulley.
  46. Remove the lower timing belt cover bolts.
  47. Remove the lower timing belt cover.

  48. Object Number: 1241553  Size: SH
  49. Slightly loosen the coolant pump retaining bolts.
  50. Remove the coolant pump counterclockwise using the J 42492-A  (1) to relieve the timing belt tension.
  51. Remove the timing belt. Refer to Timing Belt Replacement .

  52. Object Number: 1241556  Size: SH
  53. Disconnect the crankcase ventilation tube at the camshaft housing.

  54. Object Number: 1241557  Size: SH
  55. Remove the valve cover bolts.
  56. Remove the valve cover and the valve cover gasket.
  57. Important: Take care to prevent any scratches, nicks, or damage to the camshaft.

  58. While holding the camshaft firmly in place, remove the camshaft gear bolt.
  59. Remove the camshaft gear.

  60. Object Number: 1241559  Size: SH
  61. Remove the rear timing belt cover upper bolts.

  62. Object Number: 1241561  Size: SH
  63. Disconnect the ignition wires at the spark plugs.
  64. Remove the retaining nuts from the catalytic converter at the exhaust manifold flange.
  65. Disconnect the front heated oxygen sensor electrical connector.

  66. Object Number: 1241562  Size: SH
  67. Disconnect the heater inlet hose at the coolant distributor.
  68. Disconnect the surge tank coolant hose at the throttle body.

  69. Object Number: 1241564  Size: SH
  70. Remove the intake manifold support bracket retaining bolts.

  71. Object Number: 1241566  Size: SH
  72. Disconnect the throttle cable at the throttle body and the intake manifold.

  73. Object Number: 1241567  Size: SH
  74. Gradually loosen all of the cylinder head bolts in the sequence shown.
  75. Remove the cylinder head bolts.
  76. Remove the camshaft carrier assembly.
  77. 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.

  78. Remove the cylinder head with the intake manifold and the exhaust manifold attached.
  79. Remove the cylinder head gasket.

Installation Procedure


    Object Number: 1241570  Size: SH

    Caution: Valve springs can be tightly compressed. Use care when removing the retainers and plugs. Personal injury could result.

  1. Apply a continuous 3 mm (0.12 in) bead of gasket maker to the sealing surface of the camshaft carrier.
  2. Install the cylinder head gasket.
  3. Install the cylinder head with the intake manifold and the exhaust manifold attached.
  4. Install the camshaft carrier assembly.
  5. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1241571  Size: SH
  6. Install the cylinder head bolts in the sequence shown.
  7. Tighten
    Tighten the cylinder head bolts to 25 N·m (18 lb ft).


    Object Number: 1241639  Size: SH
  8. Using the J 45059 or the KM-470-B  (1), tighten the cylinder head bolts another 70 degrees plus 70 degrees plus 30 degrees.

  9. Object Number: 1241566  Size: SH
  10. Connect the throttle cable at the throttle body and at the intake manifold.

  11. Object Number: 1241564  Size: SH
  12. Install the intake manifold support bracket retaining bolt.
  13. Tighten
    Tighten the intake manifold support bracket retaining bolts to 25 N·m (18 lb ft).


    Object Number: 1241562  Size: SH
  14. Connect the surge tank coolant hose at the throttle body.
  15. Connect the heater inlet hose to the coolant distributor.

  16. Object Number: 1241561  Size: SH
  17. Install the catalytic converter nuts at the exhaust manifold flange.
  18. Tighten
    Tighten the auxiliary catalytic converter-to-exhaust manifold nuts to 40 N·m (30 lb ft).

  19. Connect the front heated oxygen sensor electrical connector.

  20. Object Number: 1241559  Size: SH
  21. Install the rear timing belt cover upper bolts.
  22. Tighten
    Tighten the rear timing belt cover upper bolts to 10 N·m (89 lb in).


    Object Number: 1241557  Size: SH

    Important: Take extreme care to prevent any scratches, nicks, or damage to the camshaft. Such damage can impair vehicle operation.

  23. Install the camshaft gear.
  24. While holding the crankshaft pulley bolt, install the camshaft gear bolt.
  25. Tighten
    Tighten the camshaft gear bolt to 45 N·m (33 lb ft).


    Object Number: 1241556  Size: SH
  26. Connect the crankcase ventilation tube to the camshaft housing.

  27. Object Number: 1241548  Size: SH
  28. Align the mark on the camshaft gear to the notch at the top of the rear timing belt cover.

  29. Object Number: 1241635  Size: SH
  30. Align the mark on the crankshaft gear to the notch at the bottom of the rear timing belt cover.
  31. Install the timing belt. Refer to Timing Belt Replacement .
  32. Inspect the timing belt tension. Refer to Timing Belt Inspection .
  33. Install the lower timing belt cover bolts.
  34. Tighten
    Tighten the lower timing belt cover bolts to 10 N·m (89 lb in).


    Object Number: 1241555  Size: SH
  35. Install the crankshaft pulley.
  36. Install the crankshaft pulley bolt.
  37. Tighten

        • Tighten the crankshaft pulley bolts to 95 N·m (70 lb ft).
        • Using the J 45059 or the KM-470-B , tighten the crankshaft pulley bolt another 30 degrees plus 15 degrees.
  38. Connect all of the vacuum hoses and electrical connectors.
  39. Connect the brake booster hose at the intake manifold.
  40. Connect the upper radiator hose at the thermostat housing.

  41. Object Number: 1241551  Size: SH
  42. Install the alternator bracket.
  43. Install the alternator bracket retaining nut.
  44. Tighten
    Tighten the alternator bracket retaining nut to 25 N·m (18 lb ft).

  45. Install the alternator nut. Do not tighten.

  46. Object Number: 1241550  Size: SH
  47. Connect the fuel feed line at the fuel rail.
  48. Notice: Refer to Belt Dressing Notice in the Preface section.


    Object Number: 1241546  Size: SH
  49. Install the serpentine accessory drive belt. Refer to Power Steering Pump Hoses and Pipes Replacement .
  50. Install the upper timing belt cover.
  51. Install the upper timing belt cover bolts.
  52. Tighten
    Tighten the upper timing belt cover bolts to 10 N·m (89 lb in).

  53. Install the A/C compressor drive belt, as necessary.
  54. Install the right front wheel well splash shield.
  55. Install the right front wheel. Refer to Tire and Wheel Removal and Installation .

  56. Object Number: 1241535  Size: SH
  57. Install the air filter housing.
  58. Install the air filter housing bolts.
  59. Tighten
    Tighten the air filter housing bolts to 12 N·m (106 lb in).

  60. Connect the air intake tube to the throttle body.
  61. Connect the breather tube to the valve cover.
  62. Connect the intake air temperature (IAT) sensor connector.
  63. Install the CMP sensor.

  64. Object Number: 1241532  Size: SH
  65. Connect the ECT sensor connector.
  66. Connect the IAC valve connector.
  67. Connect the TP sensor connector.
  68. Connect the EI system ignition coil connector.
  69. Connect the fuel injector harness connectors.
  70. Connect the O2 sensor connector.
  71. Connect the powertrain control module (PCM)/ECM ground terminal at the intake manifold.
  72. Connect the negative battery cable.
  73. Install the fuel pump fuse.
  74. Refill the engine cooling system. Refer to Cooling System Draining and Filling .