1998 Chrysler Concorde noises under the hood

So if I am understanding you correctly, if you tap on the hood of the car or the engine then the car shuts off and won't start or are you hearing a tapping noise from the engine and then it just shuts off? Does it sputter and die or just completely shut off? How often does this happen and how long does it take once you start the car? How long does it take before the car will start again?