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Home >> Chevrolet >> 2001 >> Venture Base, Van Passenger >> Repair and Diagnosis >> External Pages >> Different car >> Section 389 (Engine Mechanical - 3.1L V6 - VIN (J) Unit Repair) >> Repair Instructions >> Cylinder Head Cleaning and Inspection

Cylinder Head Cleaning and Inspection

WARNING: This page is about a different car, the 2002 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.

Tools Required: 

  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
    • Fig 1: Cylinder Head Gasket
      G01763841Courtesy of GENERAL MOTORS CORP.
    NOTE: Do not scuff the chamber.
  3. Use the J 8089 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 2: Remove The Carbon From The Combustion Chambers
      G01763842Courtesy of GENERAL MOTORS CORP.
  5. Inspect the cylinder head mating surfaces for flatness. Recondition the cylinder head mating surface, if necessary, by milling. Replace the cylinder head if you must remove more than 0.25 mm (0.010 in)
  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 3: Inspecting Cylinder Head Mating Surfaces
    G01763843Courtesy of GENERAL MOTORS CORP.
  8. Inspect the valve springs for squareness.
    Fig 4: Inspect The Valve Springs For Squareness
    G01763844Courtesy of GENERAL MOTORS CORP.
  9. Use the J 9666 in order to measure the valve spring tension. Replace the spring if the spring tension is not within specification.
    Fig 5: Inspecting Spring Tension
    G01763845Courtesy of GENERAL MOTORS CORP.