Can anyone help me diagnose this??

Have you replaced the doo yet? If not, then you have a good reason to pull off the left side cover, and replace it while you're in there. It sounds to me like the sound is coming from there anyway.

Ruddroo: did you remove the tensioner and release the spring according to the manual? You are supposed to compress the tensioner ratchet, then install the tensioner body first, then install the spring into it. If you did that, I don’t understand how you “extended it one click, then reinstalled.”

Stuffing the spring back into the tensioner requires a fair amount of force, and it has a tendency to try to push out sideways. If it seems too flimsy, measure it’s free length and post that here.

Paul or Tom or anyone: do you know what the spec is for free length? (I don’t have my manual handy).

Well, I just removed my cam chain tensioner and measured the spring. As a point of reference, it’s 3.315 inches long. If your spring is significantly shorter than that—say 10%—I’d be concerned. My 1998 has 40,000 miles on it, so it’s probably as worn-in or sacked as it’s gonna get, and it still works fine.