I have a 2010 Cooper S that makes a 3-second noise at shutdown. Best described as sticking a card in a fan until it stops. Interesting that it does NOT make the noise when the MAF is disconnected. Any ideas?

Link to recording.

Much appreciated. Thx.

 

What led you to the idea of disconnecting the MAF sensor? Is there a MAF sensor fault code?

 

No MAF code. Just forgot to reconnect the MAF when I removed the air box to diagnose and noticed it went away. Came back when I reconnected MAF.

 

The first thing that came to mind when I listened to your audio clip is the sound of a spinning turbocharger.

 

Turns out it’s the pressure converter valve. Part number

63217160897

common problem I guess

 

Nice!