vauxhall vectra cam belt problem

[blackmagic11]

Hi all!

Just done a cam belt, idlers, tensioner and water pump on the mrs sisters vectra 1.8 16 valve and the cam belt and idler is behaving a little strangley
check video on me youtube



Its timed up, tensioned up to manufactures guide (little finger pointing to cut out) and everything is brand new.
Yet the little finger is moves about and the belt vibrates like buggery at about 2000 rpm.
Ive tried it tighter and looser and tried turning the water pump alittle.
I have exhausted my brain on this one. every looks good just at around 2000 it goes all flappy:bang:

Any help would be great coz I want to enjoy my bank holiday weekend not under a vauxhall

 

[DaveMcT]

That tensioner looks like its not doing tension stuff. This is only a rough check but if the belt turns more than 90 degrees on the longest run it's too loose.