Cylinder Head Cleaning and Inspection

Special Tools

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

For equivalent regional tools, refer to Special Tools 

Fig 1: View Of Cylinder Head Gasket
Courtesy of GENERAL MOTORS CORP.
1. Inspect the cylinder head gasket and the mating surfaces. Inspect for leaks, corrosion, and blowby.
2. If the gasket failed, determine the cause. The following conditions may cause gasket failure:
   • Improper installation
   • A loose or warped cylinder head
   • Missing, off location, or not fully seated dowel pins
   • Low torque on the cylinder head bolts
   • Cylinder head bolts with the incorrect length
   • A warped engine block surface
   • Scratched surfaces
   • Excessive intake manifold torque
   • Cracked engine block threaded holes
   • Porosity
Fig 2: Cleaning Carbon Using J 8089
Courtesy of GENERAL MOTORS CORP.
WARNING: Refer to Safety Glasses Warning .
NOTE: Do not scuff the chamber.
3. Use the J-8089:  Carbon Removing Brush in order to remove the carbon from the combustion chambers.
4. Clean the following components:
   • The gasket surfaces

     Do not use a motorized brush on any gasket sealing surface.

   • Valve stems and heads on a buffing wheel
   • The bolt hole threads

     Remove all dirt, debris, or threadlocking material from the bolt holes.

Fig 3: Inspecting Cylinder Head Mating Surfaces For Flatness
Courtesy of GENERAL MOTORS CORP.
5. Inspect the cylinder head mating surfaces for flatness. Replace the cylinder head if it is outside of the specification limit.
6. Inspect the cylinder head for cracks.
7. Inspect the cylinder head deck for corrosion. Do not attempt to weld the cylinder head. If the cylinder head is damaged, replace the cylinder head.
Fig 4: Identifying Valve Components
Courtesy of GENERAL MOTORS CORP.
8. Remove the valve spring dampener.
Fig 5: Inspecting Valve Spring For Squareness
Courtesy of GENERAL MOTORS CORP.
9. Inspect the valve springs for squareness.
Fig 6: Measuring Valve Spring Tension
Courtesy of GENERAL MOTORS CORP.
10. Use the J-9666:  Valve Spring Tester in order to measure the valve spring tension.

    Replace the spring if the spring tension is not within specification.

Fig 7: Identifying Valve Components
Courtesy of GENERAL MOTORS CORP.
11. Install the valve spring dampener.