320d E46 Turbo Query

[JCO133]

I have an E46 320d and when I bought it the car it had a very audible turbo dump sound or 'whoosh' noise when accelerating through the gears (so much so my gf called it a 'wooh girl'). It no longer makes that noise and hasn't done so for a few months, but there's no noticable drop in power/boost from the turbo or anything. 

The service history has said the swirl flaps were done on the car, so I doubt it's that, anybody with any ideas on what the cause might be will be helpful as I am just a bit worried that the turbo itself is going! 

[RUSSELLM]

The original ‘whoosh’ doesn’t sound good. I’d normally associate that with an air induction leak.

Has someone connected/tightened an air pipe ?

[JCO133]

I always presumed the 'whoosh' was normal, it's not during accelerating itself per se, but when lifting off the accelerator changing gears etc. Always thought it was a turbo dump noise or something.

I doubt anyone has fiddled with it unless my BMW specialist garage has done it for free!

[Touring442]

Depend what year is is - around 2003 and the 6 speed box, BVMW fitted a turbo with an electronic actuator, replacing the old vacuum operated one. A split upper boost hose is very common but results in black smoke under boost.