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.