Does it sound like a bearing screaching or maybe a piece of debris? We had a funny noise like that for a while only on some speeds and found out a leaf got in there through the air intake. It finally worked its way out to a vent grate and we picked it outta there. How it got past the filter is a mystery...
I originally thought that, and turned the fan full blast for a few minutes. When I allowed it to return to auto climate control (and thus a lower fan speed) the noise was gone. I figured I blew the debris off, but then it returned today.
It is a high pitched noise, like a cricket almost.
well i had the exact same problem and then my blower motor went. so if you blower motor goes then we know what the problem is. LOL. when you take it out you'll problem see that it's all rusted. well the bearings. yep then you'll need one for sure. hope that helps
My c220 has a high pitch screeching noise from the vent when the temperature is really cold, and after I apply the brake. The noise is not from the brake as it continues to screech even after the car is completely stop and is idling. I can make the noise go away by turning the system on and off. This is the problem since when the car was new. Unfortunately, it happens only in real cold weather, and every time I took it to the dealer, the temperature has warmed up enough they could not hear it.
Now after so many years, it is still there, and I still have no idea what caused it.
It is located in the same access area as your cabin filter and is very easy to remove. It is held in by torx-head screws, but I don't remember which size torx. When I had a similar situation with my C280, the noise was being caused by little leaves and pieces of debris that was caught in the fan/blower assembly.
That's easy enough, thanks. I am familiar with the removal of the cabin filter. So I'll just put a new one in and take a peak around while it's out. I'm sure it's easier than the throttle actuator I just replaced (Which actually wasn't hard either.)
Took my blower motor cover off.Sound goes away when i wiggle the wires or try to wiggle the blower motor itself.Sounds like a bearing going bad i guess
Chirp Chirp 
Linear Mode
