Fan Level with Heat on? Humming Sound?
Just something I noticed now that the weather is getting colder. I always keep my climate control on "auto" at 72 degrees, on sync, and with the AC always on, as I know the dealer told me to keep it on all year. One thing I've noticed is when the car turns on, about a minute or two after, I hear a humming whistling sound when the air is blasting (warm air), lasting for about 10 seconds, and then goes away. My guess is it's the blend doors turning or something. But it sounds like someone is basically putting a piece of paper over their mouth and whistling. My mom's 2021 e350 does something similar, so I assume it's normal?
In the summer when the temperature was warm and hot, it didn't do it, my guess becuase the blend doors didn't have to turn that much? I don't know. But also, no issues with heat or anything, works great!
Has anyone noticed this?




