I'm a new owner, so this might be old question...

Did about a normal drive today, about 20 miles, half highway, half street. Nothing crazy....parked the car and heard this humming noise from somewhere in the engine bay. Is this normal? I took a short 8 second video if you can hear it in the video..

 

If you read your owners manual, it states that one of the cooling pumps may stay active after you turn the engine off, to allow the turbo to cool down properly, think of it as a factory turbo timer.

 

Interesting, I didn't know that either.

Speaking of noises, what are the various "energizing" noises made when unlocking the car, or opening doors? Some from the rear, some from the engine.

 

thanks @RMachuca !

DWooderson, my best guess is that those noises are simply the locks being unlocked. For example, if you unlock the hatch, you'll hear the noise for the unlock, and then as you lift the handle, you'll notice that lifting the handle doesn't actually disengage anything, as the hatch was already disengaged when the noise occurred. Make sense? that's my guess!

 

No, I think it's definitely an energizing noise of some sort, and it is coming from under the bonnet when I open a door.

 

I've heard the same thing. I don't think it's the locks because I hear it opening the door when the locks have already disengaged

 

It's the CAN-BUS system waking up. All newer German cars do this. It's also things like the fuel pumps (front and rear) priming. It's normal.