Federicodrdpro, here I reply to your private message.
In other forums I found nothing (other than the topic which you participated), but I found this information.
The following information comes from
ElsaWin, I do not know if this can solve the noise problem (I think so).
"Ask at your local dealer to ensure that this is the problem".
From 11/12 is being progressively implemented a new
pressure regulator built into the fuel supply unit. In this case,
suppresses the extra fuel filter including bypass return pipe.
4-Extra fuel filter. (this extra fuel filter works as a
pressure regulator).
2-Return pipe.