Cheap Blown Head Gasket Test

What you need:

  • Plastic wrap
  • Rubber band

Instructions:

  1. Place plastic wrap over top of radiator cap opening. Push in slightly, leave a 1-2 inch “U” shape in the plastic.
  2. Wrap rubber band around the plastic and seal it to the radiator neck. Pinch the overflow hose to prevent air leaks.
  3. Disable the ignition system or have someone start the engine for a few seconds.
  4. If the slack you pushed into the plastic wrap pops up, then you more likely have a blown head gasket or cracked head.