GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN 348 Valve Spring Compressor - Head Off
    • EN 46116 Valve Stem Seal Remover/Installer
    •  EN 46117 Valve Stem Key Remover/Installer
    • EN 46119 Off-Vehicle Valve Spring Compressor Adapter

For equivalent regional tool, refer to Special Tools.


    Object Number: 1210901  Size: SH
  1. Install the cylinder head coolant threaded plugs.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Tighten the cylinder head coolant threaded plug to 31 N·m (23 lb ft).

  4. Object Number: 1210891  Size: SH
  5. Install the NEW cylinder head oil gallery expansion plugs.

  6. Object Number: 1210887  Size: SH
  7. Place the valve stem oil seals onto the guides.
  8. Note: NEVER reuse a valve stem oil seal. Always use new seals when assembling the cylinder head.

  9. Mount a new valve stem oil seal using the EN 46116 installer .
  10. Note: Force should only be applied to the valve spring contact area of the new valve stem oil seal during installation.

  11. Push and twist the valve stem oil seal into position on the valve guide until the seal positively locks on the guide using the EN 46116 installer .
  12. Lubricate the valve stem and valve guide ID with clean engine oil or equivalent. Refer to Adhesives, Fluids, Lubricants, and Sealers.

  13. Object Number: 1210884  Size: SH

    Note: The valve stem oil seal must not come loose from the valve guide when the valve is installed.

  14. Insert the valve into the valve guide until it bottoms on the valve seat.

  15. Object Number: 1210879  Size: SH
  16. Position the valve spring on the spring seat.
  17. Place the valve spring retainer onto the valve spring.

  18. Object Number: 1210825  Size: SH

    Warning: 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.

    Caution: Do not compress the valve springs 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.

  19. Compress the valve spring using the EN 348 compressor and the EN 46119 adapter .

  20. Object Number: 1210911  Size: SH

    Note: Ensure proper directional placement of valve keepers in the EN 46117 installer . The valve keepers must be installed with the tapered end towards the valve stem seal.

  21. With the spring compressed, install the valve keepers into the EN 46117 installer .

  22. Object Number: 1210829  Size: SH
  23. Place the keepers into position by pushing the tool downward and releasing tension on the EN 46119 adapter and the EN 348 compressor .
  24. Verify that the valve keepers are installed by placing a rag over the valve tip and tapping with a dead-blow hammer. The valve keepers and the spring should remain in place.