GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 45059 Angle Meter

Removal Procedure


    Object Number: 1336109  Size: SH
  1. Remove the thermostat housing crossover. Refer to Thermostat Housing Crossover Replacement .
  2. Remove the intake manifold. Refer to Intake Manifold Replacement - Right Side .
  3. Remove the exhaust manifold. Refer to Exhaust Manifold Replacement - Right Side .
  4. Remove the valve rocker arm shaft, pushrods, and valve bridges. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  5. Remove the glow plugs. Refer to Glow Plug Replacement - Bank 1 in Engine Controls - 6.6L (LLY).
  6. Remove the cylinder head bolts in the sequence shown.
  7. Discard the large M12 bolts.

  8. Object Number: 1336113  Size: SH
  9. Remove the cylinder head.
  10. Remove and discard the cylinder head gasket.
  11. Clean the sealing surface of the engine block and the cylinder head.
  12. 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.

  13. Clean the cylinder head bolt holes in the engine block.
  14. For service to the cylinder head refer to the following:
  15. • Refer to Cylinder Head Disassemble .
    • Refer to Cylinder Head Cleaning and Inspection .
    • Refer to Cylinder Head Assemble .

Installation Procedure


    Object Number: 1336113  Size: SH

    Notice: The left and right cylinder head gaskets are not interchangeable. Improper placement of the cylinder head gasket will block coolant and oil passages. Blocked coolant and oil passages will cause severe engine damage.

  1. Install the cylinder head gasket of the correct grade. Refer to Cylinder Head Gasket Selection Specifications .
  2. Install the cylinder head.

  3. Object Number: 663831  Size: SH

    Notice: This component uses bolts with a preapplied molybdenum disulfide coating for thread lubrication. Do not remove the coating or use any additional lubricant. Improperly lubricated threads will adversely affect the bolt torque and clamp load. Improper bolt torque and clamp load can lead to engine damage.

  4. Install the NEW M12 cylinder head bolts.
  5. Reuse the M8 cylinder head bolts.
  6. Notice: Refer to Fastener Notice in the Preface section.

  7. Tighten the cylinder head bolts in the following steps using the sequence shown.
  8. Tighten

    1. Tighten the M12 bolts a first pass to 50 N·m (37 lb ft).
    2. Tighten the M12 bolts a second pass to 80 N·m (59 lb ft)
    3. Tighten the M12 bolts a third pass to 60 degrees, using J 45059 .
    4. Tighten the M12 bolts a final pass to 60 degrees, using J 45059 .
    5. Tighten the M8 bolts to 25 N·m (18 lb ft).
  9. Install the valve rocker arm shaft, pushrods, and valve bridges. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  10. Install the glow plugs. Refer to Glow Plug Replacement - Bank 1 in Engine Controls - 6.6L (LLY).
  11. Install the right exhaust manifold. Refer to Exhaust Manifold Replacement - Right Side .
  12. Install the right intake manifold. Refer to Intake Manifold Replacement - Right Side .
  13. Install the thermostat housing crossover. Refer to Thermostat Housing Crossover Replacement .
  14. Road test the vehicle for normal operation.
  15. Inspect for coolant, oil, or exhaust leaks.