Noisy T-belt tensioner...help

[dclose@tcadvertising.com]

Hello all,

After replacing the T-belt, water pump and tensioner on an 86 MC motor, I
now have a screeching sound from this area.
1) I loosened the tension to more than 1/2 a twist of the belt with no
change.
2) I put an old (proven quiet) w-pump in with no change.
3) I put an old (proven quiet) tensioner in and the noise is gone.

When I exchanged the tensioner for a new one, it feels exactly the same as
the noisy one. I noticed a very small amount of play in both of the new
bearings, while there is almost none in the used quiet bearing. Both the
new units are made by Febi Bilstein and are fairly stiff and not nearly as
freewheeling as the worn but quiet high mileage unit.

I will put the new one in this weekend, but if it doesn't fix it:
Is this noise common? Will the noise eventually go away? (without
destroying the T-belt!).  Am I doing something wrong with my tensioning?

This seems to be the last problem holding up the MC in the 80q project. Any
comments are appreciated!
_____
Dave