GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2002 🢒 Isuzu T-Series (Truck Line C) 🢒 Engine 🢒 Engine Controls - 7.8L 🢒 Cylinder Head Replacement

Removal Procedure
  1. Tilt the cab. Refer to Cab Tilting in General Information.

    2. Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.

  2. Disconnect the negative battery cable.
  3. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  4. Remove the air inlet pipes.
  5. Remove the Turbocharger assembly. Refer to Turbocharger Replacement in Engine Controls.
  6. Remove the intake manifold assembly. Refer to Intake Manifold Replacement .
  7. Remove the exhaust manifold assembly. Refer to Exhaust Manifold Replacement in Engine Exhaust.
  8. Remove the heat shield and bracket.
  9. Remove the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  10. Remove the valve rocker arm shaft assembly. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  11. Remove the camshaft assembly. Refer to Camshaft Replacement .
  12. Remove the fuel injector nozzles.
  13. Remove the coolant line from the air compressor to the cylinder head.
  14. Remove the glow plugs. Refer to Glow Plug Replacement in Engine Controls.
  15. Remove the air compressor line bracket from the rear of the cylinder head.
  16. Remove the cylinder head bolts from the cylinder head.
  17. Remove the cylinder head and the gasket from the engine.
  18. Inspect the threaded parts for wear or damage.
  19. Clean carbon deposits from the combustion chambers.
  20. Clean all traces of the old cylinder head gasket from the cylinder head and the engine block.
  21. Clean the cylinder head bolt threads using a wire brush.
  22. Clean metal chips and dirt from the threads in the cylinder block.

    23. Important: Use a straight edge to check the flatness of the cylinder head. If the cylinder head has more than 0.2 mm (0.0078 in) gap between the straight edge and the surface of the cylinder head, replace the cylinder head.

  23. Inspect the cylinder head for cracks or damage.

Installation Procedure

    Important: Apply sealant to the rear corners of the cylinder block before installing the cylinder head gasket with the part number facing up.

  1. Install the cylinder head and gasket to the block.
  2. Install the cylinder head bolts to the cylinder head.

    3. 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.

  3. Tighten the cylinder head bolts in the following sequence:
    4. 3.1. First pass for bolts 1-26:

    Tighten
    Tighten bolts 1-26 to 98 N·m (72 lb ft).

    3.2. Second pass for bolts 1-26:

    Tighten
    Tighten bolts 1-26 to 147 N·m (108 lb ft).

    3.3. Turn bolts 1-26 an additional 30-60 degrees.
  4. Tighten the remaining cylinder head bolts in the following sequence:

    5. Tighten
    For bolts 27 and 28 tighten to 39 N·m (28 lb ft).

  5. Install the camshaft assembly. Refer to Camshaft Replacement .
  6. Install the rocker arm shaft assembly. Refer to Valve Rocker Arm, Shaft, and Push Rod Replacement .
  7. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  8. Install the coolant line from the air compressor to the cylinder head.
  9. Install the air compressor lines and the bracket to the rear of the cylinder head.
  10. Install the glow plugs. Refer to Glow Plug Replacement in Engine Controls.
  11. Install the fuel injector nozzles.
  12. Install the exhaust manifold. Refer to Exhaust Manifold Replacement in Engine Exhaust.
  13. Install the intake manifold. Refer to Intake Manifold Replacement .
  14. Install the Turbocharger assembly. Refer to Turbocharger Replacement in Engine Controls.
  15. Install the air inlet pipes.
  16. Connect the negative battery cable.
  17. Lower the cab.