Busted DV?..... 225 BAM

[A3Tom]

Ok so its not my car but my GFs TT. I was driving it today and when you open it up over 4k revs theres a funny noise....like air escaping. Its not the normal sound of boost which it normally has..seems much louder. My first guess is the stock DV has given up the ghost, has anyone experienced a goosed DV and if so what did it cause?.

The car seems to run out of puff once the noise starts so it seems to be a big old boost leak. Its really loud inside the cabin of the car so im guessing it may be the DV becuase of its proximity to the passenger compartment.

Any opinions?. If i get chance il lob my 007 on it but wont be able to do that for a couple of days.

Ta

T

 

[S3 Paul]

I would look at the large and small rubber hoses that come from the metal upper boost pipe . Larger one goes to the DV and the smaller one goes to the N75 valve.
Ive had both of these split ( not at the same time) and it made this noise and killed the power like you say

 

[leshkin]

If you have access to VCDS, you should be able to log requested v's actual boost, that might show if the actual boost goes at the time of the power going, which would definitely point to a boost leak, which by your description is most likely.

 

[rossbrownlee]

I would say that a boost leak from a burst or detached hose is more likely than a goosed recirc valve. I had the same problem on mine, was the hose from inlet mani down to crankcase breather pcv. hooge split. hose check would be my first step. if you are on idle you should hear a leak sucking, run a finger along each hose and see if you find anything.