magic123

hey guys ive got a 2.0T audi a3 quattro on a 56 plate currently on 43k mileage, its getting i think pretty bad mpg, i drive 12miles to work one way and about 10miles of this is on a A road so can sit at a constant 70mph, whatever i do or however i drive i get 320 to a tank, it says 21.3mpg and on a run at 65mph for about 70miles i was only getting around 24mpg, when i put the clutch down to change gear i get like a twshhh noise almost like a dump valve twshh noise but not as agressive or loud, sounds like its coming from behind my steering wheel almost, it can lack power too afew tiems put my foot down and theres hardly any power, even if its at around 3/4k of revs, feels like im in a 1.0 sometimes, ive been told to check the PCV valves, DValve/divert valve and a customer (i work in insurance) said about the 02 sensor, any ideas or suggestions very welcome

Prospeeder

The crankcase vent valve has failed. they all do on 2.0Ts. Start the engine and try to remove the oil cap, i bet you cant, its just full engine vacuum on the crankcase. This will cause some very serious oil leaks quickly if you dont replace it.

ayap

Did you get the dealer to look at it ? 24 MPG is pretty low for an A3. I get 24 MPG highway on my V8 S5 at speeds of 90-100MPH on occasion and 70-75 MPH on average. You should be getting around 28 MPG.