Not too long ago I started to hear a moaning sound coming from my CLS. It sounds like the car keeps priming itself. It sounds like an electric motor whining for a good 5-8 sec. EVEN WHEN THE CAR IS OFF. U can hear it clearly at night when the car is off, and on a quiet night when the car is on. I've taken it to the dealer in hopes of finding out if that is normal or if anyone has every complained about the same noise. Thier conclusion was; 'have u noticed a loss in performance?'.
"No".
'Well then there really isn't a major problem, but we will put it on file incase this become a major problem we will know'

So my question is has anyone ever heard this before. If not, go home one day let ur car sit there or an hour or too (as if ru returning from work and have no where to go later) go outside have a couple of beers on a quiet night and wait to listen for that sound. It occurs on my CLS anywhere from 1/2 to 45 mins. . So try it out.
I'm not crazy; 'I hear noises'.

 

Its okay the people in the white jackets wont hurt you. j/k
Keep taking it back and tell them you want it fixed.

 

Ok so u never heard that sound. Well try it out. Go home, wait till its quiet, have a couple of beers and u might just hear it.

 

YOU ARE NOT CRAZY!!! I've heard this for quite some time now. Comes from the rear driver's quarter panel, right?

Sounds like:
"woooeerrrrrrrrrrrrrrrrrrrrr. woooeerrrrrrrrrrrrrrrrrrrrr."

WTF??? I have not even bothered to bring this up to dealer...

 

The electric fans can run when the car is off but that's the only thing that I caught still running once I turn her off.