E500 - hydraulic lifters tap tap tap

[David68]

Hi all - I've just bought myself a 2002 E500. First of the W211s. 100,000 miles on the nose. Lots of history and appears to have been well cared for. On acceleration it sounds faintly clattery - think of a low pitched tappet type noise. It doesn't go away when warmed up but is not audible on tickover.

I'd very much appreciate any pointers. And if it is the lifters any ideas as to how many hours this could come to?

Thanks very much, David