Excuse my techinical ignorance. I have a Ford Galaxy 1.9 tdi automatic (2002). There is a small boxed type component, which is situated roughly underneath the n/s/r door. When the car is running this makes a whirling noise and is dicharging smoke out of the pipe from this box. The pipe is open ended and is directed towards centre of chassis. What is this component and do I have a major problem? Thanks in anticipation