maybe if you read what wrote,, ie its a known weakness with all n47 diesel engines timing chains its not a made up thing whether mapped or not makes not much difference only thing that does is how hard and long rev'd hard,, by a bhp map pushing the power to top end do wear them faster if driven like it, fact torque is where a diesel should set,,
other facts all no rolling road live maps are made from a one off rolling road on a similar engine ,, trouble with generic maps they are just that all fuelling were recovered and timing and air intake even temps and air pressure etc on one day on one car that might of done 50.000 miles or 5000 miles something you would not be sure of,, so a map relies on all 02 sensors being the same and mas air flow being the same and air temps being the same as your car on that day to get best results,,, hence why my pint you totally missed was live map rolling road time is always best kind of map to have as its for that one car with any of its differences in fuel and air and timing etc,, as for mapping hurting a engine no its the stupidity of some drivers who dont know what they are doing with a mapped car,, ie all increased heat and every revs more revs more wear not me just making that up its basic understanding,, below links worth reading maybe you will understand a little better,,, not a if its a when they all do, nice to be in front of something before it happens ,, was not picking your car or your post apart, but maybe everyone else who have suffered the n47 and its £4k gift when the chain slips might feel its nice thing that someone gave them the heads up before and they replaced the chain before it went and destroyed the engine,, thats all have to say now goodluck
Timing chain repairs on BMW models 118d, 120d, 123d, 318d, 320d, 520d, 525d, 530d, 535d, X3, X5 and 730d - engine code N47, M57 & N57
prestige-german-engines.co.uk