[white 125M]

Hi all, Tried searching the forum for this topic but couldnt find anything. We've had our 125 auto for about a month and have just noticed that the engine seems quite noisy at idle as in, very tappety - it reminds me of a diesel engine. I only notice this sound from inside the car, listening from the outside, it seems normal, so i'm not overly worried about it, but having come from a 335, this engine does seem to be a bit noisier. Is this something that other owners have picked up?