Quote Originally Posted by niky View Post
Not many people do compression tests, though the equipment is pretty simple. Speedlab does compression, too.
Gasoline and diesel engines have different types of compression gauge. For gasoline engines, the pressure range is from 0- 250 psi and for diesel engines the range is from 0- 800 psi. In testing gasoline engines, you need to remove all the spark plugs and disable the ignition system and insert the test hose to the spark plug hole of each cylinder. For diesel engines,its a different story. You must have a glow plug adaptor or nozzle adaptor to fit on each cylinder for compression testing. Most of independent service shops don't have this instrument unlike the casas.