try wiggling the fan blades fore and aft there should be no play...
if there is the waterpump bearings are on their way out....
any spray on belt conditioner is short term fix and contamination, either oil or antifreeze will cause noisy belts also if the belt is too tight it will cause noise....pressing down moderatly on the
middle of the belt between pulleys you should have 1/2-3/4" deflection only.
