Re: Diesel sound on start up?
Like Hugo says it is the variator.
You should not worry...it cannot brake anything. The sound will get more and more loud with time...but if it just 2-3sec. it is perfectlly fine.
Anyways on the next timining belt change do replace the small string(speeling) together with a small plastic thing...costs about 5Euro...there is no need to replace the variator at all...the noise comes from that small spring which with time gets "loose" and starts making the ratlle noise.
Not many dealers know about that simple fact that it can be fixed with 5euro or they simply dont want to know.
For now it is perfectlly safe.
Alfa 147 QVD 300hp by BlackAngels, Alfa 159 2.4 QVD, Alfa 159 TI 1.9 QVD and Crosswagon edition Nero