Renault Gran Scenit

Bom, tenho um problema em um cenário Renault, espero que você possa me ajudar a descobrir o problema, porque nem mesmo na casa eles sabem como me dizer o que é, descrevo o mau funcionamento. It is a Turbo Diesel 120 hp engine to pass from 2,000 - 2,300 revolutions in a squeeze, that is, when the accelerator stepped together the car begins to tremble quite abruptly and to expel so much smoke than to the back or see him for the mirrors, I have changed my transmission but I doubt that this is the problem since it continues to persist, therefore I think it is the turbo ... You could help me.