BLOODY HELL !
Hopefully the noise is gone after all this .
Trouble is i doubt it. Chain was fine and tight.... My only hope now is that it was the oil seals causing the noise.
As I mentioned before, when the engine is runing, the tensioner could be flapping up and down - causing the noise. When the engine is stopped, the tensioner rests on a ratchet and so can appear fine in its fully extended (chain tight) position. This is why the noise only appears when the engine is hot (thinner oil = more tensioner flapping = more noise) and running.
I'm certainly no mechanic, but thats my summary of the 2nd hand information I gleaned on the lead up to having mine replaced (and noise banished!).
Fingers crossed for you!