Quick, easy and guaranteed? Can those terms all be used to describe anything that actually proves to be true? They can be if you’re talking about trying to determine if an A/C system is working at peak performance. It’s really an old trick that (surprisingly) isn’t used or understood by a lot of today’s technicians. But rest assured that once you understand it, you will use it every time. After all, it’s the laws of physics at work in your A/C system, and you just can’t fight the laws of physics.

On July 11, 2004, at the Porsche 928 Owner’s Club International Convention in Wichita, Kansas, a friend told Louie Ott that the first sign of a problem was when he spied a slight tongue of orange flames suddenly poking out from underneath the right front end of Louie’s 1987 S4. It was followed almost immediately by the whump of a hood-bending explosion, a red-orange ball of flames shooting out from under the car and clouds of smoke; lots of smoke. All this as Louie, trying to gauge his distance from a nearby fence, was very slowly backing out of a small parking area.