Hello together, maybe someone can tell if he/she is also aware of a ringing sound when the air conditioner is switched on at the new Sorento (built in 2015). I had the car four times in the workshop now, without success. Even a second opinion from another workshop was included on the advice of KIA. The air conditioner was tested by everyone heart and kidney, the expansion valve changed… The ringing remains and makes me crazy. KIA is only that it is a normal operating noise of the air conditioning system. Does anyone have any experience with the conversion of a vehicle in such a case? Thank you in advance…