GM Service Manual Online
For 1990-2009 cars only

    Object Number: 589370  Size: SH
  1. Remove the threaded coolant jacket plugs.

  2. Object Number: 1646930  Size: SH
  3. Remove the threaded engine block heater.

  4. Object Number: 26198  Size: SH
  5. Remove the remaining plugs using the following procedure.
  6. 3.1. Obtain a suitable self-threading screw.
    3.2. Drill a hole into the plug.
    3.3. Install the self-threading screw.
    3.4. Use the screw to pry out the plug.