Hi All looking for some help or advice.

2008 Audi A4 2.0TDI CAGA engine

A few months ago I change the cambelt and water pump and followed everything to the book, but ever since then I have suffered with bad MPG when the car is cold and on short trips averaging between 20 - 30mpg, on long runs everything seams to be normal averaging between 48 - 54mpg dependent on speed.

the above figures have been reached using tank fill meathead, but what I have noticed is when looking at the did display it shows 15mpg when first started and struggles to get to 30mpg when cold where before the cambelt was changed it would read 15mpg when first started but would then quickly move up above 38mpg and above.

the above problems seem to be like too much fuel is being injected into the engine but there is no singe of smoke or rough running at all if anything the car feels better with lots of power thought the rev range. One thing I have noticed though is the temp gauge is taking some time to get up to temp, I have changed thermostat but am wondering if the problem could be with the temp sensor?

I have scanned the car and all is good without faults and captured some data which seems fine also.


Please see attached images. I hope you may be able to throw some light as to why I am having this problem and if there are any other tests I can do to find the problem


Turbo1.jpgEngine torque.jpgAir flow.jpgfuel pressure.jpgcoolent.jpg