GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the spark plug wires. Refer to Spark Plug Wire Replacement.

  2. Object Number: 470690  Size: SH
  3. Loosen each spark plug one or two turns.
  4. Brush or air blast away any dirt from around the spark plugs.
  5. Remove the spark plugs one at a time and place each plug in a tray marked with the corresponding cylinder numbers.

Installation Procedure


    Object Number: 470690  Size: SH
  1. Properly position each spark plug washer.
  2. Inspect each spark plug gap. Adjust each plug as needed.
  3. Specification
    Spark plug gap: 1.524 mm (0.060 in)

    Caution: Refer to Fastener Caution in the Preface section.

  4. Install the spark plugs.
  5. Tighten

        • For IRON Head-all Subsequent Installations tighten the spark plugs to 20 N·m (15 lb ft).
        • For new iron heads tighten the spark plugs to 30 N·m (22 lb ft).
  6. Install the spark plug wires. Refer to Spark Plug Wire Replacement.