How to Remove Spark Plugs When the Top Has Broken Offby Contributor
Sometimes when changing spark plugs, the ceramic top can break off of one. You aren't certain what to do but don't want to have your car towed to the mechanic. There is hope. Knowing the right way to remove the spark plug after you have broken the top off is just a simple learning process.
Spray around the threaded area with a light penetrating oil like Liquid Wrench or Kano Kroil. Allow it to soak in for 20 minutes or more before trying loosen the broken plug. If this is the first spark plug that you attempted to remove, it's not a bad idea to soak the others. Usually if one is in poor shape, the others are probably not much better. Once you have decided that it has soaked enough, continue to the next step.
Get an EZOut the size that will fit the hole where the ceramic used to be. You will need a very large EZOut Extractor. An EZOut (or Easy-out) is similar to a drill, except that it turns in reverse. As you turn the EZOut counter clockwise, its teeth grip the interior more tightly and turns it.
Insert the EZOut extractor into the shaft where the ceramic part used to be. Make certain that the EZOut is the appropriate size. If it's too small, the teeth will not grip the sides.
Turn it very slowly and carefully to unscrew and remove the old spark plug.