Hello i have a disco 200tdi, last weak the timing belt snaped, so i put a new one on, changed the bent push rods i had. Its starts up great a lot quieter than before, problem is now when left, say over night and i start it up its fine but when reved up it smokes like mad until i drive about 200 yards then it stops, any idea whats causing this before i have to rip the head off.