E91 330d Strange Noise

[PM140]

Hi,

I'm trying to diagnose a strangle noise on my 2007 e91 330d MSport.

For the last 4 months I've been getting a "psst" noise when I realise my foot from the accelerator.

In recent weeks it's doing it on most journeys. It's quite audible with the windows down, especially at low speeds.

The car still pulls like a train and there are no warning lights on.

Just wondered if anyone had encountered this, before I take it to a specialist.

Thanks
Peter

[Panthro]

You sure it's not the blow off/dump/bypass valve? Mine makes this noise, it's pretty normal.

[PM140]

Good thought, but it's definitely a new sound for my car, on some journeys it doesn't make the sound at all. It's just become more frequent recently.