GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2008 🢒 G3 🢒 Engine 🢒 Engine Mechanical - 1.2L 🢒 Cylinder Head Replacement

Removal Procedure

    Object Number: 1291944 Size: SH

    Caution: Wear safety glasses in order to avoid eye damage.

  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.

  3. Disconnect the negative battery cable.

    4. Object Number: 1291942 Size: SH
  4. Drain the engine coolant. Refer to Cooling System Draining and Filling.
  5. Disconnect the positive crankcase ventilation (PCV) hose from the valve cover.
  6. Remove the ignition coil.

    7. Object Number: 1291945 Size: SH
  7. Remove the air cleaner housing bolts.
  8. Remove the air cleaner housing.

    9. Object Number: 1291946 Size: SH
  9. Disconnect the main throttle idle actuator (MTIA) connector.
  10. Disconnect the A/C pressure transducer connector.

    11. Object Number: 1291947 Size: SH
  11. Disconnect the intake air temperature (IAT) sensor connector.
  12. Disconnect the throttle cable from the throttle body.
  13. Disconnect the brake booster vacuum hose at the intake manifold.

    14. Object Number: 1291948 Size: SH
  14. Disconnect the fuel injector harness connectors.
  15. Disconnect the fuel line at the fuel rail.

    16. Object Number: 1291949 Size: SH
  16. Disconnect the camshaft position sensor connector.
  17. Disconnect the coolant temperature sensor connector.

    18. Object Number: 1291950 Size: SH
  18. Slightly loosen the power steering lower adjusting bolt.

    19. Object Number: 1291951 Size: SH
  19. Slightly loosen the power steering upper adjusting bolt.

    20. Notice: Do not use belt dressing on the drive belt. Belt dressing causes the breakdown of the composition of the drive belt. Failure to follow this recommendation will damage the drive belt.

  20. Remove the A/C with power steering drive belt.

    21. Object Number: 1291952 Size: SH
  21. Remove the upper timing belt cover bolts.
  22. Remove the upper timing belt cover.

    23. Object Number: 1291953 Size: SH
  23. Align the camshaft gear timing mark to the notch in the rear timing belt cover.

    24. Object Number: 1291954 Size: SH
  24. Slightly loosen the alternator retaining bolts.
  25. Remove the alternator drive belt.

    26. Object Number: 1291955 Size: SH
  26. Remove the engine under cover.
  27. Remove the crankshaft pulley bolt.
  28. Remove the crankshaft pulley.

    29. Object Number: 1291956 Size: SH
  29. Remove the lower timing belt cover bolts.
  30. Remove the lower timing belt cover.

    31. Object Number: 1291957 Size: SH
  31. Remove the timing belt automatic tensioner bolt.
  32. Remove the timing belt automatic tensioner.
  33. Remove the timing belt. Refer to Timing Belt Replacement.

    34. Object Number: 1291958 Size: SH
  34. Remove the camshaft gear bolt from the camshaft.

    35. Object Number: 1291960 Size: SH
  35. Remove the timing belt rear cover bolts.
  36. Remove the timing belt rear cover from the cylinder head and cylinder block.

    37. Object Number: 1291961 Size: SH
  37. Remove the heat shield mounting bolts.
  38. Remove the heat shield.

    39. Object Number: 1291962 Size: SH
  39. Remove the retaining nuts from the catalytic converter at the exhaust manifold flange.

    40. Object Number: 1291943 Size: SH
  40. Remove the valve cover with the hexagon bolts.
  41. Remove the valve cover gasket.

    42. Object Number: 1291963 Size: SH
  42. Gradually loosen all of the cylinder head bolts in the sequence shown.
  43. Remove the cylinder head bolts.
  44. Remove the cylinder head assembly from the engine block, with the intake/exhaust manifold, throttle body, water outlet case and cylinder head gasket.

Cleaning Procedure

    Object Number: 1291964 Size: SH

    Caution: Wear safety glasses in order to avoid eye damage.

  1. Clean the gasket surfaces of the cylinder head and the engine block.
  2. Make sure the gasket surfaces of the cylinder head and the engine block are free of nicks and heavy scratches.
  3. Clean the cylinder head bolts.

    4. Notice: Clean all dirt, debris, and coolant from the engine block cylinder head bolt holes. Failure to remove all foreign material may result in damaged threads, improperly tightened fasteners or damage to components.

  4. Inspect the cylinder head for warpage. Refer to Cylinder Head Cleaning and Inspection.

Installation Procedure

    Object Number: 1291965 Size: SH
  1. Install the cylinder head gasket.
  2. Install the cylinder head with the intake manifold and the exhaust manifold attached.

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Install the cylinder head bolts in the sequence shown.

    4. Tighten
    Tighten the cylinder head bolts in the sequence previously shown to 65-70 N·m (48-52 lb ft).


    Object Number: 1291943 Size: SH
  4. Install the cylinder head cover hexagon bolts.

    5. Tighten
    Tighten the cylinder head cover hexagon bolts to 9-12 N·m (80-106 lb in).

  5. Install the catalytic converter nuts at the exhaust manifold flange.

    6. Tighten
    Tighten the catalytic converter to exhaust manifold nuts to 25-35 N·m (18-25 lb ft).


    Object Number: 1291961 Size: SH
  6. Install the heat shield.
  7. Install the heat shield mounting bolts.

    8. Tighten
    Tighten the heat shield mounting bolts to 10 N·m (89 lb in).


    Object Number: 1291960 Size: SH
  8. Install the timing belt rear cover from the cylinder head and cylinder block.
  9. Install the timing belt rear cover bolts.

    10. Tighten
    Tighten the timing belt rear cover bolts to 10.5 N·m (93 lb in).


    Object Number: 1291956 Size: SH
  10. Install the timing belt. Refer to Timing Belt Replacement.
  11. Install the lower timing belt cover.
  12. Install the lower timing belt cover bolts.

    13. Tighten
    Tighten the lower timing belt cover bolts to 10.5 N·m (93 lb in).


    Object Number: 1291952 Size: SH
  13. Install the upper timing belt cover.
  14. Install the upper timing belt cover bolts.

    15. Tighten
    Tighten the upper timing belt cover bolts to 10.5 N·m (95 lb in).


    Object Number: 1291955 Size: SH
  15. Install the crankshaft pulley.
  16. Install the crankshaft pulley bolts.

    17. Tighten
    Tighten the crankshaft pulley bolts to 70 N·m (52 lb ft).


    Object Number: 1291954 Size: SH
  17. Install the A/C with power steering drive belt.
  18. Install the alternator drive belt.

    19. Object Number: 1291949 Size: SH
  19. Connect the coolant temperature sensor connector.
  20. Connect the camshaft position sensor connector.

    21. Object Number: 1291948 Size: SH
  21. Connect the fuel line at the fuel rail.
  22. Connect the fuel injector harness connectors.

    23. Object Number: 1291947 Size: SH
  23. Connect the brake booster vacuum hose at the intake manifold.
  24. Connect the throttle cable from the throttle body.
  25. Connect the IAT sensor connector.

    26. Object Number: 1291946 Size: SH
  26. Connect the A/C Pressure transducer connector.
  27. Connect the MTIA connector.

    28. Object Number: 1291945 Size: SH
  28. Install the air cleaner housing.
  29. Install the air cleaner housing bolts.

    30. Tighten
    Tighten the air cleaner housing bolts to 12 N·m 106 lb in).


    Object Number: 1291942 Size: SH
  30. Connect the PCV hose from the valve cover.
  31. Install the ignition coil.
  32. Connect the negative battery cable.
  33. Install the fuel pump fuse.
  34. Refill the engine cooling system. Refer to Cooling System Draining and Filling.