Hi Guys,
New on here.
Just thought I would add to this post - I had the same thing on my ED30 (had it for ages now, but got used to the sound). Found this post and thought I'd get it checked out with dealer (2,000 miles till end of Warranty

)
Martins at Basingstoke, put it in there on Tuesday, left it with them overnight so they could hear it in full effect. Got it back yesterday, New Cambelt/Tensioner/Pulley - no Water Pump though, but it saved me nearly 500 quid (was gonna get it done at 80k

) They never argued about it once, said it was the second ED30 they'd had with the issue.
Sounds sweet again now - ready for the next 58,000 miles!