GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN 46106 Flywheel Holding Tool
    • EN 46110 On-Vehicle Valve Spring Compressor
    • EN 46116 Valve Stem Seal Remover/Installer
    • J 39313 Spark Plug Port Adapter

Removal Procedure


    Object Number: 945978  Size: SH
  1. Remove the starter motor. Refer to Starter Motor Replacement.
  2. Important: If the EN 46106 is not installed, the crankshaft may rotate. If the crankshaft rotates, disassembly and reassembly of the entire camshaft timing system may be required.

  3. Install the EN 46106 in order to prevent crankshaft rotation.
  4. Remove the camshafts and rocker arms. Refer to Camshaft Replacement - Right Side.
  5. Remove the spark plug from the applicable cylinder. Refer to Spark Plug Replacement.
  6. Install the J 39313 to the applicable cylinder.
  7. Connect the J 39313 to a compressed air source.

  8. Object Number: 1338337  Size: SH
  9. Install the EN 46110 above the applicable cylinder as shown.
  10. Caution: Compressed valve springs have high tension against the valve spring compressor. Valve springs that are not properly compressed by or released from the valve spring compressor can be ejected from the valve spring compressor with intense force. Use care when compressing or releasing the valve spring with the valve spring compressor and when removing or installing the valve stem keys. Failing to use care may cause personal injury.

    Notice: Do not compress the valve springs to less than 24.0 mm (0.943 in). Contact between the valve spring retainer and the valve stem oil seal can cause potential valve stem oil seal damage.

  11. Tighten the EN 46110 valve spring compressor nut (2).

  12. Object Number: 902903  Size: SH
  13. Remove the valve keepers.
  14. Loosen the EN 46110 valve spring compressor nut.
  15. Remove the valve spring retainer.

  16. Object Number: 902899  Size: SH
  17. Remove the valve springs.

  18. Object Number: 1338340  Size: SH
  19. Use the EN 46116  (1) in order to remove the valve stem seal (2).

Installation Procedure


    Object Number: 1338340  Size: SH
  1. Use the EN 46116  (1) in order to install the valve stem seals (2).

  2. Object Number: 902899  Size: SH
  3. Install the valve spring.
  4. Install the valve spring retainer.

  5. Object Number: 1338337  Size: SH
  6. Install the EN 46110 above the applicable valve spring as shown.
  7. Tighten the EN 46110 valve spring compressor nut (2).


    Object Number: 902903  Size: SH
  8. Install the valve spring keepers.
  9. Remove the EN 46110 .
  10. Disconnect the J 39313 from the compressed air source.
  11. Remove the J 39313 .
  12. Install the spark plugs. Refer to Spark Plug Replacement.
  13. Install the rocker arms and camshafts. Refer to Camshaft Replacement - Right Side.
  14. Remove the EN 46106 .
  15. Install the starter motor. Refer to Starter Motor Replacement.