I`ve used engine flush on it since new and a few years back i had to change the sump pan due to the condition it was on the outside, rusted beyond belief
It`s a well known problem with the X230 and X244 series 2.8 engines in Peugeot, Fiat and Citroens.
At that stage it had done nearly 70,000 miles and i was staggered at the condition of the bottom end of the engine when i removed the old pan.
It literally was like new and the inside of the old pan had no sludge / debris in it what so ever, it was just the outside that was rusted to hell
I shall continue with my regime and i`m a little surprised we haven`t had the usual doom and gloom merchants coming on saying i`m doing it all wrong