Started 3-4 drive cycles ago. Doesn't occur on cold start, only after engine's warmed up, then it's always there. Sounds like rushing air or something spinning or air in a pipe. Increases with throttle input. Can be heard with bonnet closed or open. Seems to me more pronounced around the left front area. Here's audio for reference, can be heard more at idle due to engine and exhaust noise.

 

Ouch!!

 

I can't hear anything particularly worrying. Could be tensioner or idler pulley. Perhaps remove s/c belt and see if it goes. If not, closer inspection of accessories/pulleys driven by serpentine belt might help.

Richard

 

The only bad thing I heard was Six Grand in Neutral.

 

It’s more obvious after the down rev at the end of the video, sounds like a higher pitched hissing noise. Definitely not there when it’s cold. Also more obvious on limited dynamic range playback devices such as phones.

 

To me it sounds like the bearings are noisy on the turbo. It can last a long while.

 

Did a bit more investigating. It's loudest in the lower front left corner, in the wheel well. Used a stethoscope and the hissing noise seems to be coming from the area of the power steering pump or AC compressor, there's also an intermittent faint non-rhythmic metallic sharp ticking noise in the same lower area which slowly became more frequent and pronounced whilst troubleshooting. Turning the steering wheel has no affect nor does turning the air con off and on.

 

I would like to see that happen.

 

Its not the supercharger.

 

I had a collapsed engine mount on the left side that allowed the AC compressor pulley to make contact with the subframe. I say that only because of the "metallic click" You mention in that area.

 

So I removed the accessories belt and one by one hand spun the pulleys. All seemed normal until I arrived at the compressor pulley. It spins, but feels like it's rubbing on something and makes a rubbing noise which I reckon is the same noise observed earlier. AC blows ice cold and the noise persists whether the AC is on or off so I'd assume it's limited only to the pulley.

Any idea if the pulley can be replaced in place? I'd hate to have to do a full service when it's working perfectly fine.