In my sec car, 318d timing chain produces noise for about 50k mls now and still nothing
Its rulette - since almost every n47 have timing chain noise even f30 and f10 i assume its just normal and need to live with it.
My friend replace engine for n47d20C from X1 20d after rearended ( engine with replace cost him about 2000pounds LOL ) but after 20k mls again timing chain noise.