My Fiat Linea 1.3 MJD Emo.pk is giving me white smoke when in neutral and accelerated to 4000 rpm. And, when in running condition I can see black cloud in IRVM mirror. I remember my turbo hose was worn out twice and was replaced. Now the fiat tech is telling me that the turbo actuator is not working. The fuel efficiency is also very bad. I get 12 to 14 kmpl in display. What to do? I would like to know how the actuator really works and if its not working how to maintain it.