Cylinder Head Cleaning and Inspection

Tools Required

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

Fig 1: Removing Carbon From Combustion Chambers
Courtesy of GENERAL MOTORS CORP.
CAUTION: Refer to Safety Glasses Caution in Cautions and Notices.
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.
   • 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.

Fig 2: View Of Cylinder Head Components
Courtesy of GENERAL MOTORS CORP.
2. Inspect for the following conditions:
   1. The cylinder head (218) for cracks in the exhaust ports and combustion chambers
   2. The cylinder head for external cracks in the water chambers
   3. The gasket surfaces for excessive scratches or gouging

      Refer to Replacing Engine Gaskets .

   4. The bolt hole threads for debris or damaged threads

      Refer to Thread Repair or Thread Repair Specifications .

Fig 3: Inspecting Cylinder Head For Warpage
Courtesy of GENERAL MOTORS CORP.
3. Inspect the cylinder head for warpage.
Fig 4: Inspecting Valve Spring For Squareness
Courtesy of GENERAL MOTORS CORP.
4. Inspect the valve springs for squareness.
Fig 5: Measuring Valve Spring Tension
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).