GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 8089 Carbon Removal Brush
    • J 9666 Valve Spring Tester

For equivalent regional tools, refer to Special Tools.

    Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 4957  Size: SH

    Note: 

       • When cleaning a cylinder head in a thermal type oven, do not exceed 204°C (400°F).
       • Be careful not to scuff the chamber.

  1. Clean the following components:
  2. • Use the J 8089 brush in order to remove the carbon from the combustion chambers.
    • Gasket surfaces
      Refer to Replacing Engine Gaskets.
    • Valve stems and heads on a buffing wheel
    • Bolt hole threads
      Remove all dirt, debris, or threadlocking material from the bolt holes.
  3. Inspect the cylinder head for the following conditions:
  4. 2.1. Cracks in the exhaust ports and combustion chambers
    2.2. External cracks in the water chambers
    2.3. Gasket surfaces for excessive scratches or gouging

    Refer to Replacing Engine Gaskets.

    2.4. Bolt hole threads for debris or damaged threads

    Refer to Thread Repair or Thread Repair Specifications.


    Object Number: 1552456  Size: SH
  5. Inspect the cylinder head for warpage. Refer to Engine Mechanical Specifications.

  6. Object Number: 4960  Size: SH
  7. Use the J 9666 tester in order to measure the valve spring tension. Refer to Engine Mechanical Specifications.

  8. Object Number: 2046466  Size: SH
  9. Inspect for a leaking plug. Second design applications use a rivet-type plug at the top rear coolant passage of each cylinder head. If service of a leaking plug is required, it is necessary to remove the cylinder head from the engine to properly remove the plug. Refer to Cylinder Head Disassemble