GM Service Manual Online
For 1990-2009 cars only

Tools Required

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

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


    Object Number: 4957  Size: SH

    Important: 

       • 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 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: 64318  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 in order to measure the valve spring tension. Refer to Engine Mechanical Specifications .