GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    Caution: Refer to Battery Disconnect Caution in the Preface section.


    Object Number: 1803612  Size: SH
  1. Disconnect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .
  2. Remove the engine dress cover. Refer to Fuel Injector Sight Shield Replacement .
  3. Remove the ignition coil retaining bolts (1) and remove the ignition coils (2). Refer to Ignition Coil Replacement - Bank 1 and Ignition Coil Replacement - Bank 2 .
  4. Notice: This engine has aluminum cylinder heads. Do not remove the spark plugs from a hot engine, allow it to cool first. Removing the spark plugs from a hot engine may cause spark plug thread damage or cylinder head damage.

  5. Using a suitable spark plug socket, loosen the spark plug slightly and then re-tighten to break away any carbon deposits on the threads.
  6. Loosen the spark plug once again one or two turns, then use compressed air to remove any foreign material that may otherwise enter the combustion chamber.

  7. Object Number: 1803608  Size: SH
  8. Remove the spark plug (1).
  9. Repeat as required for the remaining spark plugs.
  10. Important: Place each spark plug in the same order as that of removal. This will enable any abnormal spark plug condition to be identified with the cylinder. If the spark plugs are removed for an indefinite period before installation, plug the spark plug openings to prevent foreign particle ingress.

  11. Use a feeler gage to check the spark plug gap. If the gap is not within specifications, replace the spark plug.
  12. Inspect the spark plugs if required. Refer to Spark Plug Inspection .

Installation Procedure

    Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1803682  Size: SH

    Notice: Be sure plug threads smoothly into cylinder head and is fully seated. Use a thread chaser if necessary to clean threads in cylinder head. Cross-threading or failing to fully seat spark plug can cause overheating of plug, exhaust blow-by, or thread damage. Follow the recommended torque specifications carefully. Over or under-tightening can also cause severe damage to engine or spark plug.

    Important: The use of anti-seize compound or similar lubricant on the spark plug threads is not required.

  1. Using a suitably sized rubber tube attached to the spark plug terminal post, hand start each spark plug (1) into the cylinder head thread.
  2. Tighten
    Tighten the spark plug to 18 N·m (13 lb ft).

  3. Install the ignition coil. Refer to Ignition Coil Replacement - Bank 1 and Ignition Coil Replacement - Bank 2 .
  4. Install the fuel injector sight shield. Refer to Fuel Injector Sight Shield Replacement .
  5. Connect the negative battery cable. Refer to Battery Negative Cable Disconnection and Connection .