2004 Chevy Impala Serpentine Belt

The only way your serpentine belt can affect your engine temperature is if it stretches out too much. In this case the belt slips on the pulley resulting in squealing and lack of performance from the water pump (as well as all the other pulleys). It's easy to replace and cost around $15. You should also check your belt tensioner: If the spring is worn, the belt will be loose on the pulleys as well (cost: around $45). There are more possible causes for your problem, so make sure you check your level of coolant, and check for leaks. It is also possible that your cooling system needs to be flushed, or maybe your thermostat is messing with you.