GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Engine 🢒 Engine Mechanical - 6.0L 🢒 Spark Plug Replacement

Removal Procedure
  1. Remove the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .

    2. Notice: Allow the engine to cool before removing the spark plugs. Attempting to remove the spark plugs from a hot engine may cause the plug threads to seize, causing damage to cylinder head threads.

    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.

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

    3. Object Number: 14824 Size: SH
  3. Loosen each spark plug 1 or 2 turns.
  4. Brush or use compressed air to remove any dirt 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: 14824 Size: SH
  1. Inspect each spark plug gap. Adjust each plug as needed.

    2. Specification
    Spark plug gap: 1.016 mm (0.040 in)

  2. Hand start the spark plugs in the corresponding cylinders.

    3. Notice: Refer to Fastener Notice in the Preface section.

  3. Tighten the spark plugs.

    4. Tighten

        • For cylinder head-new--Tighten the spark plugs to 20 N·m (15 lb ft).
        • For cylinder head-all subsequent installations--Tighten the spark plugs to 15 N·m (11 lb ft).
  4. Install the spark plug wires. Refer to Spark Plug Wire Replacement .
  5. Install the engine sight shield. Refer to Upper Intake Manifold Sight Shield Replacement .