Cylinder Head Cleaning and Inspection

Tools Required 

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

Important:  When cleaning a cylinder head in a thermal type oven, do not exceed 204°C (400°F).

1. Clean the following components:

   Important:  Be careful not to scuff the chamber.

   • Use the J 8089  in order to remove the carbon from the combustion chambers.
     Fig 1: Removing Carbon From Combustion Chambers

     Courtesy of GENERAL MOTORS CORP.
   • 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.

2. Inspect the following:
   1. 2.1. The cylinder head (1) for cracks in the exhaust ports and combustion chambers
   2. 2.2. The cylinder head for external cracks in the water chambers
   3. 2.3. The gasket surfaces for excessive scratches or gouging

      Refer to REPLACING ENGINE GASKETS  .

   4. 2.4. The bolt hole threads for debris or damaged threads

      Refer to THREAD REPAIR  or THREAD REPAIR SPECIFICATIONS  .

   Fig 2: Identifying Cylinder Head Components

   Courtesy of GENERAL MOTORS CORP.
3. Inspect the cylinder head for warpage.
   Fig 3: Inspecting Cylinder Head For Warpage

   Courtesy of GENERAL MOTORS CORP.
4. Inspect the valve springs for squareness.
   Fig 4: Inspecting Valve Springs For Squareness

   Courtesy of GENERAL MOTORS CORP.
5. Use the J 9666  in order to measure the valve spring tension.
   • Replace the LS1 spring if the spring tension is less than 310 N (70 lb) at 45.75 mm (1.80 in).
   • Replace the LS6 spring if the spring tension is less than 400 N (90 lb) at 45.75 mm (1.80 in).
   Fig 5: Measuring Valve Spring Tension

   Courtesy of GENERAL MOTORS CORP.