GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Isuzu 🢒 2008 🢒 Isuzu H-Series 🢒 Engine 🢒 Engine Mechanical - 7.8L 🢒 Cylinder Head Replacement

Removal Procedure
  1. Remove the engine cover. Refer to Engine Cover Replacement .
  2. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  3. Drain the cooling system. Refer to Cooling System Draining and Filling .
  4. Remove the charge air inlet pipe. Refer to Charge Air Cooler Inlet Pipe and Outlet Pipe Replacement .
  5. Remove the exhaust gas recirculation (EGR) pipe. Refer to Exhaust Gas Recirculation Pipe Replacement .
  6. Remove the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement .
  7. Remove the turbocharger assembly. Refer to Turbocharger Replacement .
  8. Remove the intake manifold assembly. Refer to Intake Manifold Replacement .
  9. Remove the exhaust manifold assembly. Refer to Exhaust Manifold Pipe Replacement .
  10. Remove the heat shield and bracket.
  11. Remove the drive belt. Refer to Drive Belt Replacement .
  12. Remove the cooling fan. Refer to Fan Replacement .
  13. Remove the turbocharger coolant line retainer from the cylinder head.
  14. Remove the turbocharger coolant line from the right side of the cooling fan adapter.
  15. Disconnect the cooling line from the left side of the cooling fan adapter.
  16. Remove the 5 bolts and the cooling fan adapter from the cylinder head.
  17. Remove the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  18. Remove the valve rocker arm shaft assembly. Refer to Valve Rocker Arm and Shaft Assembly Removal .
  19. Remove the camshaft assembly. Refer to Camshaft Replacement .
  20. Remove the fuel injectors. Refer to Fuel Injector Replacement .
  21. If equipped, remove the coolant line from the air compressor to the cylinder head.
  22. Remove the glow plugs. Refer to Glow Plug Replacement .
  23. If equipped, remove the air compressor line bracket from the rear of the cylinder head.

    24. Object Number: 1581125 Size: SH
  24. Remove the cylinder head bolts from the cylinder head in the numerical order shown in the illustration.
  25. Remove the cylinder head and the gasket from the engine.
  26. Inspect the threaded parts for wear or damage.
  27. Clean carbon deposits from the combustion chambers.
  28. Clean all traces of the old cylinder head gasket from the cylinder head and the engine block.
  29. Clean the cylinder head bolt threads using a wire brush.
  30. Clean metal chips and dirt from the threads in the cylinder block.

    31. Important: Use a straight edge to inspect 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.

  31. 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. Object Number: 1564513 Size: SH
  2. Apply molybdenum grease to the large head bolts (M14 bolts).
  3. Apply clean engine oil to the small head bolts (M10 bolts).
  4. Install the cylinder head bolts to the cylinder head.

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

  5. Tighten the cylinder head bolts in the following sequence:

    6. Tighten

        • First pass: Tighten bolts 1-26 to 98 N·m (72 lb ft).
        • Second pass: Tighten bolts 1-26 to 147 N·m (108 lb ft) plus an additional 30 to 60 degrees.
  6. Tighten the remaining cylinder head bolts in the following sequence:

    7. Tighten
    For bolts 27 and 28--Tighten to 38 N·m (28 lb ft).

  7. Install the camshaft assembly. Refer to Camshaft Replacement .
  8. Install the rocker arm shaft assembly. Refer to Valve Rocker Arm and Shaft Installation .
  9. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  10. If equipped, install the coolant line from the air compressor to the cylinder head.
  11. If equipped, install the air compressor lines and the bracket to the rear of the cylinder head.
  12. Install the glow plugs. Refer to Glow Plug Replacement .
  13. Install the fuel injectors. Refer to Fuel Injector Replacement .
  14. Install the exhaust manifold. Refer to Exhaust Manifold Pipe Replacement .
  15. Install the intake manifold. Refer to Intake Manifold Replacement .
  16. Install the turbocharger assembly. Refer to Turbocharger Replacement .
  17. Install the EGR valve. Refer to Exhaust Gas Recirculation Valve Replacement .
  18. Install the EGR pipe. Refer to Exhaust Gas Recirculation Pipe Replacement .
  19. Install the cooling fan adapter to the cylinder head with 5 bolts.
  20. Connect the left side coolant line to the cooling fan adapter.
  21. Using a new gasket, install the turbocharger cooling line to the cooling fan adapter.

    22. Tighten
    Tighten the cooling line to 25 N·m (34 lb ft).

  22. Install the turbocharger cooling line to the cylinder head with clamp and fasteners.
  23. Install the cooling fan. Refer to Fan Replacement .
  24. Install the drive belt. Refer to Drive Belt Replacement .
  25. Install the charge air inlet pipe. Refer to Charge Air Cooler Inlet Pipe and Outlet Pipe Replacement .
  26. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  27. Install the engine cover. Refer to Engine Cover Replacement .