Since winter, my car has made a roaring sound on start up that mainly disappears quickly, but sometimes persists for 5 seconds or so. It is difficult to describe but sounds a little like extreme induction roar but is not rev related. I mentioned it when the car was recently serviced but nothing was mentioned when I collected it. Also it has now developed a slight hesitancy on gentle to moderate acceleration while still warming up like a mild misfire. Are these things related? Does anybody else have the roar? Thanks in advance

Can't say I've had the same only thing is the revs sometimes rise to about 1500 rpm for about 30 secs before moving back to the usual 700 - 800 rpm idling range, but as you say yours isn't revs related only strange noise I seem to have is taking the key out the engine seems to click loudly a few times like a computer resetting. Sounds like it could be related wonder if it is similar to the 1.4 tsi misfire at start up some topics have mentioned? What fuel are you using?

I have had that too. It isn't every time, and it only lasts a second or two if it does it. After that it runs perfect.

I'm on momentum and have run it for the 4 tankfuls so far as it seems to give me the best economy. Mine also starts at 1200 - 1500rpm but the noise usually goes before the revs fall. It did cross my mind as to whether it may be a fuel issue as the hesitation has only recently developed.