Today I noticed something about our Smart cdi 451 Bj. ’07 (ca. 86tkm on the clock) which makes me think. During the acceleration the turbo whistles clearly audible during the charging pressure!! This was definitely not the case before! Although you have heard the turbo on the switched off radio something, but by far not to this extent as it is now the case. No matter which gear, as soon as you speed up one hears a clear whistle from behind. Sounds of course good, but is that healthy?? Especially because this was not the case before. Does a turbo damage occur??? Hope not!