It happens on a 2008 1.8TSI Leon. When car idles the average fuel consumption rises by 0.1l every 30sec. or so while the realtime consumption stays the same ( 0.8l/h) . I started with some 12 l/100km and ended up with over 17 l/100km just by sitting in the same spot and waiting. The idle RPM is at 750 and stays there. Did anyone have a problem like this one?