GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Mechanical - 6.5L 🢒 Cylinder Head Replacement

Removal Procedure

    Object Number: 400331 Size: SH
  1. Disconnect the battery negative cable. Refer to Battery Cable Replacement in Engine Electrical.
  2. Remove the air cleaner assembly from the engine. Refer to Air Cleaner Assembly Replacement in Engine Controls-6.5L-L65.
  3. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.

    4. Object Number: 339320 Size: SH
  4. Remove the engine access panel (in the cab).
  5. Remove the drive belt from the vehicle. Refer to Drive Belt Replacement .
  6. Remove the upper intake manifold from the lower intake manifold. Refer to Intake Manifold Replacement .
  7. Remove the lower intake manifold from the cylinder head. Refer to Intake Manifold Replacement .
  8. Remove the exhaust manifolds from the cylinder head being serviced. Refer to Exhaust Manifold Replacement .
  9. Remove the turbocharger from the engine block. Refer to Turbocharger in Turbocharger.
  10. Remove the valve rocker arm cover from the cylinder head being serviced. Refer to Valve Rocker Arm Cover Replacement .
  11. Remove the valve rocker arm shaft and pushrods from the cylinder head being serviced. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  12. Remove the left accessory bracket from the cylinder head.
  13. Remove the right accessory bracket from the cylinder head.
  14. Remove the wiring harness from the engine block.
  15. Remove the thermostat housing crossover from the cylinder heads. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.
  16. Remove the cylinder head bolt (5) from the cylinder head and drain the engine block.
    17. • Insert a copper tube 1/4 or 3/8 inch 12 to 18 inch long into the cylinder head bolt hole.
    • Siphon the coolant from the engine block. This will greatly reduce the amount of coolant entering the cylinder bore when the cylinder head is removed.
  17. Remove the cylinder head bolts (in sequence) cylinder head being serviced.

    18. Object Number: 59803 Size: SH
  18. Remove the cylinder head from the engine block.

    19. Object Number: 311338 Size: SH
  19. Remove the cylinder head gasket from the engine block.

    20. Object Number: 68330 Size: SH
  20. Disassemble the cylinder head. Refer to Cylinder Head Disassemble .
  21. Use a wire brush in order to clean the cylinder head bolt threads.
  22. Clean any metal chips or dirt from the threads in the engine block.
  23. Clean and inspect the sealing surfaces of the engine block. Refer to .

Installation Procedure

    Object Number: 311338 Size: SH

    Important: DO NOT use a sealer on the head gasket. The head gasket is manufactured with the correct amount of sealant "printed" on its surface. Additional sealer may cause leakage or malfunction. Some sealers may damage the sealant that is already on the head gasket.

  1. Assemble the cylinder head. Refer to Cylinder Head Assemble .
  2. Install the head gasket to the engine block.

    3. Object Number: 59803 Size: SH
  3. Install the cylinder head on the engine block.

    4. Object Number: 362141 Size: SH
  4. Apply thread sealant to the bolt threads and underneath the bolt heads.
  5. Install the cylinder head on the engine block.

    6. Object Number: 60278 Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  6. Use the following four steps in order to tighten the cylinder head bolts:

    7. Tighten

    1. Tighten all of the bolts to 25 N·m (20 lb ft).
    2. Tighten all of the bolts to 75 N·m (55 lb ft).
    3. Tighten all of the bolts to 75 N·m (55 lb ft).
    4. Tighten all of the bolts, in sequence, an additional 90 to 100° (¼ + turn).
  7. Install the push rod, valve rocker arm, and shaft on the cylinder head that is being serviced. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  8. Install the valve rocker arm cover on the cylinder head. Refer to Valve Rocker Arm Cover Replacement .
  9. Install the turbocharger assembly to the engine block. Refer to Turbocharger .
  10. Install the exhaust manifold to the cylinder head. Refer to Exhaust Manifold Replacement .
  11. Install the glow plugs to the cylinder head.
  12. Install the thermostat housing coolant crossover to the cylinder heads. Refer to Engine Coolant Thermostat Replacement in Engine Cooling.
  13. Install the left accessory bracket to the cylinder head.
  14. Install the right accessory bracket to the cylinder head.
  15. Install the lower intake manifold to the cylinder heads. Refer to Intake Manifold Replacement .
  16. Install the upper intake manifold to the lower intake manifold. Refer to Intake Manifold Replacement .
  17. Install the wiring harness to the engine block.

    18. Object Number: 339320 Size: SH
  18. Install the engine access panel (in the cab).
  19. Install the drive belt on the pulleys. Refer to Drive Belt Replacement .
  20. Fill the cooling system with the correct quantity and grade of coolant. Refer to Cooling System Draining and Filling in Engine Cooling.
  21. Fill the crankcase with the correct amount of engine oil.