We had the engine running fixing a different issue and noticed an odd clicking noise.
The first approach was to spray water on each pulley and see if the noise stopped for a bit and then returned. This narrowed down the search, bit was difficult to isolate the exact pulley.
The next step was to remove the belt and spin the pulleys and see which one made an odd noise. The belt is easily removed with a 1/2″ breaker bar and pulling the tensioner over to release the tension.
With the belt removed the pulley spinning revealed the idle pulley was squeaking. A 14mm took the pulley off and revealed the bearing was missing some balls.
Tried to find the pulley, but that was unsuccessful, so a little cleaning revealed the bearing model, 6203lua. With this information I was able to buy two replacements bearings at NAPA for $5.00 each.
Remove the retaining click, beat out the bearings using a large socket. Pound the new ones in using the old ones to beat on. Clip the retaining clip in and mount on engine.
Viola, that noise is gone. Now on to the next noise.