GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 1998 🢒 DeVille 🢒 Engine 🢒 Engine Electrical 🢒 Spark Plug Replacement

Removal Procedure
  1. Remove the intake manifold cover.

    2. Important: Use care when removing the spark plug boots from the spark plugs. Twist the boot ½ turn before removing and the pull on the boot only. Do not pull on the wire as this may cause damage to the spark plug wire.

  2. Remove the spark plug wire from the spark plug.
  3. Remove the spark plug from the cylinder head.

Installation Procedure

    Important: Make sure the spark plug is properly gapped before installation.

  1. Install the spark plug into the cylinder head.

    2. Tighten
    Tighten the spark plug to 15 N·m (11 lb ft)

  2. Install the spark plug boot onto the spark plug.
  3. Install the intake manifold cover.