AKS4

OK, long story short. I have a 2k S4 with the APR 93 oct chip, Milltek superdual, stock DP's, 2nd set of turbos (according to previous owner) and settign at 100k miles. I recently, like within the last month have been getting a tweetybird/fluttering type of noise when I am coming off throttle. Usually most noticeable around 40mph or so. I have noticed it is dependant on engine speed rather than actual speed, and it quiets or goes away when I disengage the clutch (I.E. foot to the floor, or coasting) I am still making good boost, and all other systems seem to be a go.

I have STFA and found these 2 posts which might mean it is my wastegate. Anyway to check for sure (minus new turboes) and what is my time limit? Also, from my symptoms, any other ideas of what it might be? I replaced my DV's with 710's ~38k ago for reference and upon checking a week ago seemed fine.

Here are the 2 threads..
https://forums.audiworld.com/s4/msgs/1135904.phtml
https://forums.audiworld.com/s4/msgs/1112164.phtml<ul><li><a href="https://forums.audiworld.com/s4/msgs/1135904.phtml">https://forums.audiworld.com/s4/msgs/1135904.phtml</a</li></ul>

VandyS4

Tweetybird/fluttering sound isn't your turbos.

LMSI-G35X

I get the same thing too, and I am wondering what it is?

AKS4

I took it in for service, the dealer heard it but couldnt find where it was coming from. After checking the joints, axles, undercarriage everything looked fine with no leaks/interference.

Woudl really like to fix it. Places or things to look at?

VandyS4

Could be a boost leak from a torn TBB/DVs (although they usually just sound like rushing air and a loss of boost is almost invariably involved), wastegate. Others will chime in with better ideas.

AKS4

was they were in essence tied together on our cars. As in, if replacing wastegate, replace turbo's. I could very well be wrong (and hope so)

VandyS4

I don't think so. Make a new thread.