GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 8062 Valve Spring Compressor
    • J 9666 Valve Spring Tester
    • J 43963 Valve Spring Compressor (off car)

    Object Number: 412478  Size: SH

    Notice: In order to avoid damage, install the spark plugs after the cylinder head has been installed on the engine.

  1. Install NEW cylinder head plugs. Coat the plugs with sealer GM P/N 12345382 (Canadian P/N 10953489) or equivalent.
  2. Inspect the valve springs for the following conditions:
  3. • Expanded height
    • Unparallel spring ends
    • Spring tension using J 9666
    • Any distorted springs should be replaced

    Object Number: 412480  Size: SH
  4. Assemble the valves.
  5. Use the following steps to measure valve runout:
  6. 4.1. Apply a dab of Prussian blue on the entire valve face. Seat the valve but do not rotate it. The Prussian blue traces transferred to the valve seat are an indication of concentricity of the valve seat.
    4.2. Clean all traces of Prussian blue.
    4.3. Apply a dab of Prussian blue on the valve seat and repeat the check. The traces of Prussian blue transferred to the valve face indicates valve face concentricity.

    Object Number: 412477  Size: SH
  7. Replace the valves, if required.

  8. Object Number: 1403906  Size: SH
  9. Install the new valve seals. Fully seat the seals on the valve guides.

  10. Object Number: 1403902  Size: SH
  11. Install the springs.

  12. Object Number: 1403900  Size: SH
  13. Install the retainer.
  14. Using the J 8062 and the J 43963 , compress the valve spring.
  15. Install the valve keys.
  16. Slowly release the J 8062 and the J 43963 from the valve/spring assembly.
  17. Inspect for proper valve key seating.
  18. Install the remaining valves, springs, and other components.
  19. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1244844  Size: SH
  20. Install the cylinder head air bleed tube.
  21. Tighten
    Tighten the tube to 15 N·m (11 lb ft).

Special Tools

    • EN-8062 Valve Spring Compressor
    • EN-9666 Valve Spring Tester
    • EN-43963 Valve Spring Compressor (off car)

For equivalent regional tools, refer to Special Tools.


    Object Number: 2128104  Size: SH

    Caution: In order to avoid damage, install the spark plugs after the cylinder head has been installed on the engine.

  1. Install NEW cylinder head plugs (1). Coat the plugs with sealer GM P/N 12345382 (Canadian P/N 10953489) or equivalent.
  2. Inspect the valve springs for the following conditions:
  3. • Expanded height
    • Unparallel spring ends
    • Spring tension using EN-9666 tester
    • Any distorted springs should be replaced

    Object Number: 2146353  Size: SH
  4. Assemble the valves (1).
  5. Use the following steps to measure valve runout:
  6. 4.1. Apply a dab of Prussian blue on the entire valve face. Seat the valve but do not rotate it. The Prussian blue traces transferred to the valve seat are an indication of concentricity of the valve seat.
    4.2. Clean all traces of Prussian blue.
    4.3. Apply a dab of Prussian blue on the valve seat and repeat the check. The traces of Prussian blue transferred to the valve face indicates valve face concentricity.

    Object Number: 2148531  Size: SH
  7. Replace the valves (1), if required.

  8. Object Number: 2148530  Size: SH
  9. Install the new valve seals (1). Fully seat the seals on the valve guides.

  10. Object Number: 2148529  Size: SH
  11. Install the springs (1).

  12. Object Number: 2148527  Size: SH
  13. Install the retainer (1).
  14. Using the EN-8062 compressor and the EN-43963 compressor (off car) , compress the valve spring.
  15. Install the valve keys.
  16. Slowly release the EN-8062 compressor and the EN-43963 compressor (off car) from the valve/spring assembly.
  17. Inspect for proper valve key seating.
  18. Install the remaining valves, springs, and other components.
  19. Caution: Refer to Fastener Caution in the Preface section.


    Object Number: 2128103  Size: SH
  20. Install the cylinder head air bleed tube (1) and tighten the tube to 15 N·m (11 lb ft).