Hi need some help please. My Impreza diesel been sat for about a year but been serviced. But now developed about of whit smoke. The garage as took it for a good run the smoke now only happens till it gets warm which is better than all the time. Not using water or oil all levels are good. So could this be injectors and if so where are they located 

thanks Matt 

Hi - not sure how injectors could generate white smoke as there sole purpose is to put diesel into your air flow. White smoke for me means coolant is being burnt at the same time as your fuel / air mixture. Keep an eye on your coolant.

You will get white smoke out of your pipes until warm with most vehicles, more visible when its colder outside, is it possible you just hadn't noticed that before?