Saw this post on the FB page and replied. That said, here it is again:
- No you can't adjust the tensioner, and any attempt to over tighten it will cause the 19mm nut to break
- The noise is most likely the waterpump, but remove the belt and spin the pulleys freely to feel for resistance/noise/any wobbling, etc.
- Try installing the belt backwards, (you still need to line up the ribs with the pulley though), but pull the belt off, rotate it 180 degrees and reinstall. It sounds crazy, but sometimes this solves the squeaking, assuming that's what you're hearing.