I think my recirculating dump value is knackered - as I get a air/whoosing noise when I lift my foot of the accelerator (very loud if I drop the clutch at the same time).

However, when I accelerate it also sounds like there is air escaping from somewhere too (car just sounds wheezey). Could that also be coming from the dump-valve?

Many thanks
Richard.

 

Yeah, check the recirc pipe for splits. I had the same thing happen to my 93 WRX's moulded recirc pipe on the turbo inlet elbow: massive split in it, so the dv was partially dumping to atmos, so was acting like a vta and making a mild TSSSH! noise when coming off boost...

...BUT...

...It's more likely to be any one of a multitude of split/disconnected pipes of the boost control system, if you're hearing leaking type noises on-boost. I'd check all the major ones first, then the smaller ones to/from the BCS, etc.

If everything checks out, then remove the TMIC and check for splits in the feed pipe or unsecured/leaking flanges, etc...

 

Thanks for that - much appreciated