[s-cars] Whoosh Sound on Lift from Accelerator??

[John Cody Forbes]

The bypass valve is venting air exactly like a BOV does, just back in to the air intake tract. It's possible, even likely, that you are hearing the bypass valve functioning properly. It's also possible you have a boost leak somewhere that opens up under high intake pressure.

-Cody (mobile)

On Nov 26, 2010, at 7:52 PM, Tony Curran <tony.curran at sympatico.ca> wrote:

> I have a whoosh sound whenever I lift foot off the accelerator, for example
> when changing gear. It sounds a bit like a blow off valve vent but I have a
> regular bypass valve (new). Also happens if just motoring along then lifting
> off the gas. Does not happen when stationary.
> 
> 
> 
> It was most pronounced when I had a K&N cone filter. But with stock box and
> filter it is very slight - have to turn radio and HVAC off to hear it.
> 
> 
> 
> Any thoughts on what this might be? Something broken in the turbo?
> 
> 
> 
> I have recently replaced the turbo intake hose, MAF and spark plugs. The
> michelin man is a Samco. Turbo to x-over hose looks OK. X-over pipe is
> metal.
> 
> 
> 
> Any insight appreciated.
> 
> 
> 
> PS - anyone know why the moderator has to allow ALL of my posts - sometimes
> it is several days before they appear on the list.
> 
> 
> 
> Tony
> 
> 96 S6
> 
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