A Belt, A Bearing, and A Bad Deal

1. Goes to Auto Zone, buys an alternator, because that seems to be where the noise is coming from.
2. Noise is still there – bad Auto Zone alternator?  Probably.
3. Auto Zone checks the alternator, which passes muster on their machine in the electrical sense, but the noise can be heard on the stand.  Another reman AZ alternator doesn’t make the noise and does pass electrically.
4. Noise is still there.
5. James replaces the idler, belt tensioner, and the belt.  Noise is still there.  Puts the old belt tensioner back on.
6. James (at his wits end by this time), comes to see his instructor for a quick fix.  He didn’t bring his old belt or belt tensioner – left ‘em at home.  We take the fan off so the wind won’t over power the sound of the whining and so we can listen without losing fingers.
7. The noise is really loud around the belt tensioner area for sure.  I (the instructor) call the parts store and have them send a tensioner for a trial… noise is still there with the new tensioner.
8. Using the stethoscope as a listening pipe, I carefully listen at where the belt is hitting the pulleys – noise is really loud at point of contact, and I’m thinking the fluted cuts (see photo) across the serpentine ridges are whistling.  Notice also that the belt is very shiny – unusual for a new belt, but Auto Zone says this is the new deal with belts.  Didn’t see a brand name on the belt, but it is stamped “Made in U.S.A.
9. Ordered a Gates belt from Auto Value parts house.  No fluted cuts on the Gates belt. No noise with the Gates belt and the old tensioner.