GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 22794 Spark Plug Port Adapter
    • J 5892-D Valve Spring Compressor
    • J 38606 Valve Spring Compressor
    • J 38820 Valve Seal Installer

Removal Procedure

  1. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
  2. Remove the valve rocker arm cover from the cylinder head. Refer to Valve Rocker Arm Cover Replacement .
  3. Remove both heater hoses from the heater core. Refer to Heater Hoses Replacement in Heating Ventilation and Air Conditioning.
  4. Remove the spark plugs from the cylinder head. Refer to Spark Plug Replacement in Engine Electrical.
  5. Remove the valve rocker arm (s) from the cylinder head. Refer to Valve Rocker Arm and Push Rod Removal .

  6. Object Number: 563807  Size: SH
  7. Install the J 22794 to the spark plug hole in the cylinder head.
  8. Apply compressed air in order to hold the valve in place.
  9. Tap the valve spring cap with a soft-faced hammer in order to loosen the valve keys.

  10. Object Number: 349589  Size: SH
  11. Install an 8 mm x 65 mm bolt with a hardened washer into the rocker arm bolt hole.
  12. 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.

  13. Use the J 5892-D in order to compress the valve spring.
  14. 10.1. Hook the slotted end of J 5892-D under the washer on the bolt.
    10.2. Apply steady pressure on the valve spring cap until the valve keys are accessible

    Notice: Completely engage the J 38606 jaws on the valve spring. The J 38606 may slip off and scratch the valve spring. Replace the valve spring if the valve spring becomes scratch.


    Object Number: 563813  Size: SH
  15. Use J 38606 when there is not enough clearance to use J 5892-D .

  16. Object Number: 193264  Size: SH
  17. Remove the valve keys.
  18. Carefully release the spring tension.
  19. Remove the J 5892-D or the J 38606 .
  20. Remove the valve spring cap.
  21. Remove the valve spring.
  22. Remove the valve stem oil seal.
  23. Clean and inspect all parts. Refer to Cylinder Head Cleaning and Inspection .

Installation Procedure


    Object Number: 193264  Size: SH

    Important: The LN2 Engine uses a unique valve spring seat and seal combination unit. Under no circumstances should this seal and seat unit be replaced with a different type of seal. Use care to ensure that the valve stem seal and spring seat are not damaged during installation. Do not use excessive force or a hammer to install the seal on the guide. The seal will go on if straight and properly lubricated using hand pressure only.

  1. Lubricate the outside of the valve guide and the valve seal with clean engine oil.
  2. Using the J 38820 install the valve spring seat and seal unit onto the guide. Push and twist the valve seal into position on the valve guide until the spring seat flange is flush with the cylinder head surface.
  3. Set the valve spring in place.
  4. Set the valve spring cap in place.
  5. 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.


    Object Number: 349589  Size: SH
  6. Compress the valve spring with the J 5892-D .
  7. Notice: Completely engage the J 38606 jaws on the valve spring. The J 38606 may slip off and scratch the valve spring. Replace the valve spring if the valve spring becomes scratch.


    Object Number: 563813  Size: SH
  8. Use the J 38606 if the clearance does not permit the use of the J 5892-D .
  9. Install the valve keys.
  10. Use grease in order to hold the valve keys in place.

  11. Carefully release the valve spring pressure making sure the valve stem keys stay in place.
  12. Notice: The valve stem keys must correctly seat in the valve spring cap. Engine damage may occur by not installing properly.

  13. Remove the J 5892-D or the J 38606 .
  14. 9.1. Look to ensure that the valve stem keys seat properly in the groove of the valve stem.
    9.2. Tap the end of the valve stem with a soft-faced hammer in order to seat the valve keys if necessary.
  15. Remove the J 22794 from the cylinder head.
  16. Remove the 8 mm x 65 mm bolt and washer.
  17. Install the valve rocker arms to the cylinder head. Refer to Valve Rocker Arm and Push Rod Installation .
  18. Install the spark plugs to the cylinder head. Refer to Spark Plug Replacement in Engine Electrical.
  19. Install both heater hoses on to the heater core. Refer to Heater Hoses Replacement in Heating Ventilation and Air Conditioning.
  20. Install the valve rocker arm cover. Refer to Valve Rocker Arm Cover Replacement .
  21. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.