Hey guys. So my wife has been complaining each time she gets in the car and starts it, apparently when its cold, it makes crazy noises. Today she took a video and said for the first time it started to make the noise after only unlocking, the car hadnt been started yet. I thought maybe the 48V system is gearing up or some pumps but the sound is super loud also and I've never heard such a thing in any S class I've owned prior.

I've attached the video she made for me lol..

Is the sound coming from everywhere inside the car or does she hear it in a localized area of the cabin?

It sounds like its coming from the front of the interior cabin. Usually i start the car remotely whenever I get in when its cold but for whatever reason she never does, smh. In the summertime though when the temperature is warmer, I never hear this noise it only appears to be happening since the weather has gotten cold.

Could it be the pre-conditioning? Some of the new W223's will blow air before the car is started.

Maybe I dunno though.. It only started when the weather got cold, I thought maybe its the 48Volt system doing something. Im hoping somewhere here knows wtf it is lol

Just an educated guess, but it might be the "pre-entry climate control." Do you have this feature/button on your center console? (it also in the settings menu of course). See attached pic

That button I believe is only for the Plug-In models.

Should be for EQ Boost (48 V battery cars) and EQ Power models (plugin hybrid).

But not standard, at least not on the EQ Boost (48 V battery cars).

I see, odd though as I cannot see it as any option in the European price list. Standard on the plug-in hybrid.

I don't think I have this button in the car, I'll check when I get in it today.. Strange how this only happens when its cold, anyone else have this same noise ?