Problems with my Giulietta

Hi everyone, after doing 40k miles in three years on my Giulietta (I bough it new in 2011) it started having some problems. Sometimes when turning left it did strange noises but I didn't get too worried cause it was an occasional thing. When I took it for its check the garage didn't find any problems with it (they took it for a drive to try and hear that noise but nothing).
After three months it's still doing it but more often than before. Does anyone have this problem? What could it be?
Thanks :)