I think you are referring to a cylinder leakage test which is just as good. Get the piston on which ever cylinder you're testing at Top Dead Center of the compression stroke. You need to make sure that the transmission is in gear or hold the crank pulley secure with a wrench because when you hook up the air to it sometimes it will blow the piston down. If the leakage test is low then you should have good compression.Kalypso123 wrote:its not a dumb question. honestly i get annoyed when i ask simple questions and on one answers. its a good thing to want to learn.
a compression test is done by using a air compressor and a hose, you pump air into each cylinder through the spark plug hole. and seal around it, so it doesnt get out. ( there is a special tool for this i believe )
then use a gauge to check the PSI in each cylinder.
it should be nearly identical for all 4 cylinders.
basically you force air into each cylinder, and see if it holds the air without loosing pressure.
thats a vague description but thats how it works.search and you'll probably find threads that explain this with pics.