GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

Notice: Observe the following service precautions:

   • Allow the engine to cool before removing the spark plugs. Attempting to remove spark plugs from a hot engine can cause the spark plugs to seize. This can damage the cylinder head threads.
   • Clean the spark plug recess area before removing the spark plug. Failure to do so can result in engine damage due to dirt or foreign material entering the cylinder head, or in contamination of the cylinder head threads. Contaminated threads may prevent proper seating of the new spark plug.
   • 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.

  1. Turn OFF the ignition.

  2. Object Number: 47610  Size: SH
  3. Remove the spark plug wires from the spark plugs. Refer to Spark Plug Wire Replacement .
  4. Remove the spark plugs from the engine.

Installation Procedure

    Notice: It is important to check the gap of all new and reconditioned spark plugs before installation. Pre-set gaps may have changed during handling. Use a round wire feeler gauge to be sure of an accurate check, particularly on used plugs. Installing plugs with the wrong gap can cause poor engine performance and may even damage the engine.

  1. Gap the spark plugs to the specifications. Refer to Ignition System Specifications .
  2. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 47610  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.

  3. Install the spark plugs to the engine.
  4. Tighten
    Tighten the spark plugs to 25 N·m (18 lb ft).

  5. Install the spark plug wires to the spark plugs. Refer to Spark Plug Wire Replacement .