Video of the noise:
https://www.youtube.com/watch?v=ra6q9qCMUbI
Upper guide removed - slight scratches visible
chain also got some slight scratches
New chain tensioner ordered.
update status after i replaced it.
Old Tensioner VS New Tensioner
(new one got some finer teeth and looking generally "stronger" or thicker, seems to be taller but its just the bump thing on the outside)
By the way. The chain tensioner needs oil pressure to work fine.
So better check your oil pressure first.
PROBLEM SOLVED: new tensioner installed + upper mount deinstalled
http://www.youtube.com/watch?v=Wlh010XCos8