I have a 6 week old 3.0tdi S-Line. The engine will not pick up when in 4th or 5th gear when rpm is low at 1100/1200 abd doint 30/35mph, it's as if the gearbox is in the wrong gear, engine very slowly picks up untill turbo kicks in at 1600/1700 rpm.
Has anyone had this problem or has any ideas ??
Dealer says there is nothing wrong, but there demonstator is not like it ?

adaptive gearbox will change this if you are a bit more agressive.
Remember to keep using the same key!
You might also try putting it in sport mode just to see the difference when it occurs.

These TDis are very torquey and resist too many downshifts which is generally good.

Finally are you in comfort or auto setting if on air? Try auto, I am sure I read somewhere it is more responsive than comfort.