[IndianPoweredE90]

After you turn the engine off and wait for a few minutes u can hear this sorta like "retracting" noise. well how do i explain retracting? like something thats closing or opening. i hope you have an idea of what i mean. but anyways anyone know what it is?

[Blk07335i]

I'm not sure but I've heard it's the water pump running to cool down the turbos after the engine turned off. Not sure though.

[lkraven]

The 335i continues to circulate air/water (one, the other, or both, not sure) after you shut down the engine to gradually cool off the turbos. This is done to prevent thermally shocking the turbos with exciting results the next time you hit boost.

Also, I believe the car also blows air through the vents for awhile afterwards-- this is to prevent condensation from the AC from sitting in the vents and growing mold.

[G35revup]

its all the hot piping cooling off..makes retracting noises..

[hands on]

mine makes this winding down noise...sorta sounds like a jet engine

[ADHD]

seriusly sometimes it sounds like something crawls down the dash like a min later!

[Soni]

I am wondering too cuz I hear those noise as well....

[NPDAN]

I know I've heard the water pump cooling the turbos... The other noises I've heard kind of sound ike when you lock and unlock the doors. I hear it almost everytime I get within a certain perimeter of the car...IDFK

[bsavic]

I don't think the sound is from anything cooling the turbos, since I hear the same sound described in my 328xi...

Savic

[ADHD]

Originally Posted by NPDAN

I know I've heard the water pump cooling the turbos... The other noises I've heard kind of sound ike when you lock and unlock the doors. I hear it almost everytime I get within a certain perimeter of the car...IDFK

exactly the way to describe it!! like a light unlock of the door locks it sounds like seriusly IDFK either!!