Turbo Whistle

[Tonks4x4]

Hi Chaps,. SteveT63 is the proud owner of an S4 tonight with the AAN.
However when it comes on boost there is a whistle like a boost leak.

I have checked for boost leaks and the system holds pressure fine.
The WGFV I have swapped for another known working item.
I have swapped the DV for a miltek one.
I have checked the wastgate diagphram for tears.
I have checked the turbo impellor for endfloat and nothing seems amiss there either.

After the last test run it went like stink...... on several 0-60 runs then it seems like it wont boost again. (No pipes blown off). Park up for a min then go again it takes off like a rocket again.

No boost gauge to check what it is producing though...

But still this strange turbo whistle??????

Any Ideas???????

PS. When we got back from the second run there were flames coming from both front wheels
(Something to do with Steve's heavy work boots lol)

[Puglife]

what pressure is it making under boost?? and where were the flames from front wheels???

[Tonks4x4]

what pressure is it making under boost?? and where were the flames from front wheels???

Hi, as I said there is no boost guage fitted so we could not see what it was boosting.
And the flames were from the brakes.... The S4 is a big old heavy bus and with standard brakes it did'nt take Steve long to cook them....

[Jamo]

Cracked exhaust manifold, have you checked the vacuum hose at the ecu?

[GazzaG60]

id have gone for a heat related item. maybe a crack in the hotside.

ecu lowering boost on poor ait.

[shark_90]

Hi, as I said there is no boost guage fitted so we could not see what it was boosting.
And the flames were from the brakes.... The S4 is a big old heavy bus and with standard brakes it did'nt take Steve long to cook them....

It doesn't take Steve long to cook just about any brakes

[quattro20v]

What does the cars boost guage say? First thing on the computer. S4 have this from the factory.

[shark_90]

What does the cars boost guage say? First thing on the computer. S4 have this from the factory.

No they don't!

Edit - I might be totally wrong about that of course?

[Jamo]

No they don't!

Edit - I might be totally wrong about that of course?

Yep the S4 had a digital boost gauge AFAIK, the S2 does not have one.