GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Tools Required

J 38491 Spark Plug Heat Shield Removal Tool

  1. Turn OFF the ignition switch.

  2. Object Number: 47611  Size: SH
  3. Disconnect the plug wires from the spark plugs. Refer to Spark Plug Wire Harness Replacement .
  4. Notice: Clean the spark plug recess area before removing the spark plug. Failure to do so could result in engine damage because of dirt or foreign material entering the cylinder head, or by the contamination of the cylinder head threads. The contaminated threads may prevent the proper seating of the new plug. Use a thread chaser to clean the threads of any contamination.

  5. Remove the spark plugs from the engine.

Installation Procedure

    Notice: Use only the spark plugs specified for use in the vehicle. Do not install spark plugs that are either hotter or colder than those specified for the vehicle. Installing spark plugs of another type can severely damage the engine.

    Notice: Check the gap of all new and reconditioned spark plugs before installation. The pre-set gaps may have changed during handling. Use a round feeler gage to ensure an accurate check. Installing the spark plugs with the wrong gap can cause poor engine performance and may even damage the engine.

  1. Measure the spark plug gap on the plugs to be installed. Compare to gap specification given in Spark Plug Usage . Correct the gap if necessary.
  2. Notice: Be sure that the spark plug threads smoothly into the cylinder head and the spark plug is fully seated. Use a thread chaser, if necessary, to clean threads in the cylinder head. Cross-threading or failing to fully seat the spark plug can cause overheating of the plug, exhaust blow-by, or thread damage.


    Object Number: 47611  Size: SH
  3. Install the spark plugs to the engine.
  4. Tighten
    Tighten the spark plugs to 15 N·m (11 lb ft).

  5. Connect the spark plug wires to the spark plugs in the proper position. Refer to Spark Plug Wire Harness Replacement .