The owner of a car complains of a whistle or hiss only after the engine is shut down and only when the air-conditioning has been running. Technician A says there is a broken or leaking vacuum hose inside the dash. Technician B says this is a normal noise caused by the pressure of the refrigerant equalizing after the engine is turned off. Who is correct?

Question

Quizplus · Accepted Answer

The noise described is typically a normal occurrence due to the refrigerant pressure equalizing in the air conditioning system after the engine is turned off.

The Owner of a Car Complains of a Whistle or Hiss