Please help...Turbo flutter ?

**uzone02** · 09-05-2016 01:13 AM

I just bought a B6

But dunno why there is an Turbo flutter issue

like this clip -> https://www.youtube.com/watch?v=oJgHdWle-Yk

Please kindly help :(

ps* I have changed the DV to Forged 007, seems like no help
pss* Replace the N75 racing valve with the Original N75 valve, no help
psss* I found there a different from my old B6, which is, my old B6, the vacuum line above the air box is connect to the intake manifold, but now is connected to the DV...
(New B6) then the intake manifold vacuum is connected to the turbo inlet pipe

Thanks guys

**B6_A4_Kid** · 09-05-2016 09:17 AM

Boost leak

**uzone02** · 09-05-2016 01:53 PM

Originally Posted by B6_A4_Kid

Boost leak

but the sound comes out when u release the pedal

**old guy** · 09-05-2016 02:04 PM

Do you have the Forge 007 recirculate or the Forge 007 splitter valve?

**EuroxS4** · 09-05-2016 03:45 PM

possible dv is installed incorrectly???

**KHARDa4** · 09-05-2016 05:12 PM

Try running the dv vacuum line directly off the manifold. Possible the n249 isn't sending the vacuum signal to the dv to open, you could be hearing compressor surge because the boost pressure cannot be relieved.

EDIT : or the n112 I get them mixed up to which is for the combi valve and which is the dv

**old guy** · 09-05-2016 05:32 PM

N249 is the DV modulation valve. The default is to allow the vacuum to pass through. When activated it connects the DV directly to the vacuum canister.

**B6_A4_Kid** · 09-05-2016 05:40 PM

I had a broken check valve and it would flutter when I let off. Almost ordered a new DV, which would have been a waste.

**Rootbeer** · 09-05-2016 08:49 PM

That flutter sound is air flowing through the turbo backwards. Did you install the Forge DV after the problem started or did the problem start after you installed the new DV? I had the flutter problem on a 20th anniversary GTI and it was because the DV was sticking. A clean up and lubrication solved that problem. Some people get the flutter after installing the Forge 007 and using too stiff of a spring. Some people have been able to remove the flutter by putting in the softer spring.

**texasboy21** · 09-05-2016 09:45 PM

Did you connect the vac line to the DV?

**uzone02** · 09-06-2016 02:54 AM

Originally Posted by EuroxS4

possible dv is installed incorrectly???

yea, I tried both Normal and Reverse direction.

No help.

:(

- - - Updated - - -

Originally Posted by old guy

Do you have the Forge 007 recirculate or the Forge 007 splitter valve?

it's a Forge 007 recirculate, which is used on my previous B6, it works perfectly

**uzone02** · 09-06-2016 02:58 AM

Originally Posted by KHARDa4

Try running the dv vacuum line directly off the manifold. Possible the n249 isn't sending the vacuum signal to the dv to open, you could be hearing compressor surge because the boost pressure cannot be relieved.

EDIT : or the n112 I get them mixed up to which is for the combi valve and which is the dv

Which mean the vacuum line from intake manifold connect to DV ?

**uzone02** · 09-06-2016 03:04 AM

Update on #1

psss* I found there a different from my old B6, which is, my old B6, the vacuum line above the air box is connect to the intake manifold, but now is connected to the DV...
(New B6) then the intake manifold vacuum is connected to the turbo inlet pipe

Sorry for my poor english

**diagnosticator** · 09-06-2016 03:08 AM

The way your new B6 DV is connected sounds wrong from your description. The most likely reason for the turbo flutter is because the DV is mis-connected and is not opening when the accelerator pedal is released/throttle valve closed. Refer to the vacuum hose diagram for the correct connections.

2002>06/2003

1 - DV

21 - N249

07/2003>

2 - DV.

23 - N249 solenoid valve

The DV is connected to control vacuum at the intake manifold via the N249 solenoid valve. DV > N249 > Vacuum port, at #1 cylinder intake manifold.

The dates for the diagrams is the production date. Despite this, my A4 production date is 11/2002 and was built with the late 2003 vacuum system. Regardless, both diagrams, the DV is connected the same way.