why is c230 making a winding noise when I put on the auto mode ..

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! The mystery of the whining Mercedes? Let's figure it out! That noise you're hearing could be caused by several different things. One possibility is that the noise comes from the HVAC system's blower motor. Over time, these motors can wear out or accumulate debris, causing them to make noise when they operate. An issue with the fan blades or motor bearings could create a whining or winding sound when the auto mode kicks in. Lastly, sometimes, a loose or worn belt in the HVAC system can also cause strange noises when the system is engaged. To pinpoint the exact source of the noise, it's best to have a mechanic inspect your vehicle. They can diagnose the issue and recommend the necessary repairs to keep your heater running quietly and efficiently. If you have any other questions, please call us at 877-913-1554! We'll gladly find you a certified RepairPal shop in your area!