hi
please check this,i hear this sound every time i put the key in ON position, sometimes i hear it also while driving but not too frequent.

thanks

 

video is private.....

 

now it is working

 

What is active when "the key is on" ? HVAC Fan etc.?

.

 

the sound is always there, whether the A/C is on or not, but i noticed this sound also when ON/OFF the A/C from the button with 0.

 

any w 211 owner, please tell if you hear the same sound when key ON or A/C ON/OFF

 

I definitely don't hear that.

 

thank you, starbrite

 

I removed the ac fan and filters under the gloves box, the sound is very clear there but I still couldnt find out exactly from where.

 

Don't hear that either, hmmm

 

i have never heard such a sound.

 

my cabin blower motor bushings are dried out and I hear the same sound on the first 2 lowest speeds

 

This is most likely the problem.

OP does it sound like a hamster wheel?

I have the same issue. I have owned four diffrernt German cars 2 new 2 pre owned since 2001 and all four of them have had the same issue. They must get them from the same store. Never an issue with other cars.

 

If your fan is on 0 as stated is off.
My fan is running . The fan bushing on mine require either a lube or oil.
I would need a low temp product.?

 

I removed the fan and still hear that sound.

 

There is a secondary fan blower albeit very small one , I could be wrong might want to check on that.
That would explain the higher pitch, maybe a command sound ?