Beloved Friend I'm italian and I wanted to signal you that to 50000 km the same problem has been taken place on mine c5 hdi 130 cv. My mechanic has taken apart the motor controlling upsets to variable geometry. This in fact did not distribute the just power and therefore it decreased in the distribution. He has changed the turbine and the deflussore of the diesel oil having resolved the problem. the machine was in guarantee therefore has not spold nothing. hello