w205 - noisy AC Fan?

[elan362]

The A/C fan in my (new to me - second hand) S205 is noisy - to me, unacceptably noisy - there is a definite whirring noise that is noticeable at idle that appears to be linked to the A/C fan speed. at full chat, there is a pronounced vibration in the cab and to me the noise and vibration is coming from the passenger side dash area - is this normal or normal or abnormal?
the car has 12 months MB warranty so I'll get it looked at but just canvassing to see if this is a common issue?
Thanks

 

[elan362]

update / resolution to this.
Took the car into MB dealer today - they had it up on the ramps and I had it back in 20 min with the problem solved. They said they cleared out debris / leaves from around the AC fan motor - and all is quiet...
silence!