"Whooshing" sound from fan - R171 SLK

[Gollom]

Getting a kind of whooshing/breathing sound when ventilation fan is on - disappears when fan turned off. No difference in volume when fan going faster. If any help, the aircon needs recharging as not very cold

Any ideas for likely culprit?

Thanks

 

[BTB 500]

Try turning the aircon off. If that stops the noise then it will be coming from the compressor, and you probably have a leak in the system so the lubricant (as well as the gas) has gone.