Belt would be my primary guess... but at high mileage due to age, I would also say the idler belt pulley (bearing inside) are shot too... along with his belt adjuster shock... About $100 will cover everything.
He has a "nut" to tighten or loosen the belt tensioner pulley... once he loosen that, he can work on everything else with ease. It would be better to move the fan along with the shroud to get to everything easily.