Change to Turbo `dump` noise?

[Homer]

As far as I know the turbos don't spool on an auto in neutral or park so I'd think that was normal.... unless someone with some actual knowledge cares to correct me!

 

You may well be right there! But why would you hear the wastegate operate (and so loudly) if no positive boost is made? (Waits to be corrected... )

[Homer]

This may be a totally stupid question, but could the fluttery noise just be turbo stall? As in the wastegate / actuator etc is blocked, and on lift off all the air is going straight back through turbo no1?

 

I've heard somewhere that the sound of the turbo blades being stopped suddenly by backpressure can cause that fluttery noise..... but again that may be complete rubbish

 

That might also make sense, as I said before the EGCV arm didn't move at least when blipping while parked, maybe resulting in all pressure being sent to the turbo.

 

My gut feeling is that an actuator/valve is playing up somewhere!

[Scoboblio]

Going from my experience with an auto, you don't get any positive boost in neutral, but the air that builds up at WOT is enough to sound the BOV quite loudly

 

My boost gauge reads exactly 0 (no boost and no vacuum) when in neutral at WOT.

[letmeshowyou]

Homer did you go out in it and is the second turbo coming online?

[Homer]

I've driven BPU cars for so long it hard to know for sure. There is no noticable transition phase so it is possible the 2nd turbo is not coming online. There's no boost gauge fitted so it all 'seat of the pants' guesswork!!!

 

I've already recommended that the car should go to Max-GT or Pheonix as soon as he can

[VIL]

Cheers for the input guys. Homer did take it out but as usual with Reading it was basically `gridlock` everywhere so we could not really get it up to speed to check properly. I will run her up tomorrow on the way to work to be sure that No2 is coming in OK, but to my knowledge everything on 2 seems to be fine. No unusual loss in power etc.