Hissing noise when car hits boost???

[Jamied]

Over the last few months I've noticed the dv chatter getting louder and louder when I let off the revs, now all of a sudden when the car starts to boost it starts hissing making a 'pssssssss' noise louder and louder until I let off the revs, could this be a knackered dv valve, I've just ordered a new gfb dv+ from balance Motorsport to hopefully sort out the problem??

any help would be appreciated car is an 07 S3

thanks Jamie

 

[nothingness]

Sounds like a wastegate to me. Probably a failing spring.