hi
it all down to diesel in the oil from either leaky injectors or blocked dpf
so change the oil regular and keep an eye on oil level, if it goes up between checks you have issues
diesel dilutes the oil, its not a very good lubricant and you get heat generated by the main bearing, centre one fails first, cranks gets that hot it weakens and snaps, worse case senario, but its quite common
so keep an eye on your oil
cheers
Joe