Compression test is normally used to determine (partial) condition of engine Unlike a compression test, a leak down tester has two gauges and requires a compressed air source. Leak down test is normally used to determine what's the fault with engine but it will also give you leak down number that can be used to determine (the same partial) condition of the engine.
How To Perform A Compression And Leak-Down Test | FCP Euro
Like a compression test, a leak down test is accomplished by replacing a spark plug with the tester hose
