Just been out in the MH to give the wife some experience driving it before our trip to France next week (I will make no comments about women drivers!). I noticed what I can only describe as a slight tappet noise when the engine was under load (I think she has a heavier right foot than I do!). This is not present at constant speed. Engine is a Peugeot 2.2 HDi (2006) with 18k on the clock . I've very little experience of diesel engines so just thought I'd throw this observation in for people's comments. It's not very pronounced, but is a sort of dull clicking sound when accelerating.