A loose or slipping engine belt or a misaligned accessory drive pulley could cause a car to squeal upon acceleration. Engine belts and drive pulleys are used to power the water pump, air-conditioning compressor and the alternator of an automobile.
Engine belts should be checked every 6 months. Loose belts can be tightened, but worn out belts should be replaced. A broken belt can cause additional damage to the engine that can be costly to repair.
Most belt problems are caused by fatigue. High belt tension, excessive slippage, belt overloads and adverse environmental conditions are the main causes of belt fatigue.