Squeal or shrieking noise upon start up, especially when cold. Sudden loud, thumping noise from engine compartment while driving accompanied by an alternator light, loss of power steering, and eventually engine overheating.
The squealing comes from a worn or glazed belt that is slipping on a pulley. Pulleys function to drive and tension the serpentine belt or to operate accessories such as the alternator, power steering and water pump, or the A/C compressor. Belts that are on the verge of failing will often have a shiny or glazed appearance, will show cracking or separation, or have damaged areas such as nicked edges. Pulleys that serve to tension the belt have simple bearings that do wear out, causing a growling sound from a running engine. When the bearing develops enough resistance, in worst cases locking up, the friction of the moving belt will melt the pulley wheel and eventually snap the serpentine belt, resulting in the more severe symptoms mentioned previously. This failure will leave you stranded.
Routinely inspect the belts and pulleys for cracks, glazing, or other deterioration. Pay attention to growling noises. To avoid the inconvenience of a breakdown, replace these items at the first sign of failure.