Advice: Drive Belts

Tiny cracks in a serpentine belt aren't necessarily bad, but the deep ones here mean it's running out of time. Because this belt was removed to replace an alternator, the mechanic replaced it with a new one to save trouble down the road.

This is the inspection or replacement of the belt(s) in your engine compartment.

Every car has a water pump, a power-steering pump and various accessories - all of which are powered by rubber drive belts. On older cars, each of these components is driven by its own belt. On most modern cars, all of these components are driven by one belt, called a serpentine belt.

Is there any maintenance required between intervals?

Between service intervals, inspect your car's belts for cracks. If you hear a screeching noise coming from under the hood - especially when you start your car on a cold morning or when making a sharp turn - you might have a loose belt.

Car Talk Tip: If you're changing a serpentine belt, draw yourself a diagram of where the belt runs so you'll know exactly how to install the new one.

Should I do this service when it's recommended?

Definitely.

Why do I have to do this?

Belts in your car don't last forever. They wear out from use and eventually crack and decay from ozone that's in the air.

What happens if I don't do this?

If your car has individual belts and one of them breaks, then you'll lose the function of whatever part that belt was powering, such as the alternator, power-steering pump or water pump. If the serpentine belt breaks, all of these parts will stop functioning. Engine damage may result from overheating.