As some may know, my a3 went into an Audi VW specialist in cardiff, with a suspected blown turbo at 45k.
It came back out, with a new air intake pipe, (the large plastic one at the top) Before it went in, it sounded like a police siren, and loss of power. It came out, the main mechanic told he took of the turbo and inspected it, he said theres nothing wrong with it, showed me a graph of my car on boost, everything is normal. He said these turbos can make a bit of noise after being mapped. But i still wasnt convinced this amount of noise is normal even if the turbo fine, its amost like its struggling.
Now it sounds not as bad as it went it, but still doesn't sound 100%, and the fiance whilst driving behind me this morning noticed alot of white smoke, so i phoned up the guy, and told him, he did say when i pulled off from him that he noticed some aswell, but thought it was because the turbo has been on and off the car. But went onto say if i use supermarket, I said yes as its cheaper and on the way to work so quicker to me!
He said the supermarket fuel may be causing the white smoke as its not burning correctly in the engine, as maybe causing the turbo to sound like its struggling, as the siren noise is worst when the car has turbo lag.
As i only have less than quarter of a tank, i will run this theory, what do you think?