Redesigned timing chain guide

[PigFilth]

My 318d (2010) had to have a "redesigned timing chain guide" fitted at 19K as there was an intermittent "sss-sss-sss-sss" noise coming from the engine whilst idling and driving; at 29K it seems to be starting again - is this a known problem on this engine/does anyone have any experience of this? It was off the road for 3 days last time and the problem went away but it is not recurring.

Cheers,
C.