Additionally, if you are having belt issues, it could be an indication that they are original and need to be replaced. That's also an indication that the cooling system has not been replaced. After about 80,000 miles, the plastic pieces in these cooling systems becomes brittle, can break catastrophically, and quickly ruin an engine.
It may be time for a complete cooling system replacement including: belts, hoses, water pump, radiator, coolant reservoir, thermostat, thermostat housing, and if it's a 1.9: two more plastic pieces on the engine.
If that has been done, I would consider idler pulleys. A mechanic can usually quickly isolate the noise using a piece of hose or stethoscope.