[Capt Kirk]

I haven't heard it used for cars but my plane mechanic uses a special compression tester on my plane that allows compressed metered air into the cylinder when it's at TDC. If there's a problem cylinder, he can tell if it's leaking past the rings or either of the valves.
Would noise be of a frequency similar to a lifter tapping? Sounds like the exhaust valve on #1 and the only thing I can think of is a sticky guide.