whirring noise on E-320

[john brooks]

when the car has been stood a few hours there is a loud whirring sound(not unlike the wing mirrors opening) from under the bonnet. at a recent service the manager told me this was the breaking system priming itself.Is this normal?Surely I shouldn't be able to hear it!
Reasurance please

 

[television]

Hi John, our cars can make sounds when turned off, what car is it 124,210 or 211

 

[john brooks]

Hi Malcolm, My car is an E-CLASS 320 CDI

 

[television]

If it is 2002 on and a 211 it will be the SBC brakes charging, and mine does that with the SBC on my 230 SL

 

[stumpy]

Sounds normal for a pre facelift 211