The serpentine drive belt is a key component that helps power all of your vehicle’s engine accessories. Now imagine if your drive belt suddenly broke as you’re driving along. You may not immediately know it, but a lot of critical systems rely on your drive belt, and the sudden loss of one can quickly put your car out of commission.

Why Do Drive Belts Break?

Serpentine belts don’t last forever. Like any other engine part, drive belts will wear out over time and eventually need replacement. Most belts last between 60,000 and 90,000 miles, with some belts capable of making it to 100,000 miles or more, depending on their quality and construction.

Old, worn belts can lose their elasticity and turn brittle, making them more likely to snap apart. Belts with physical damage, including cracks or fraying along the ribs or the belt edges, can also break without warning.

Consequences of a Broken Drive Belt

Several things can happen once your serpentine drive belt breaks:

  • The alternator stops charging the battery. Without a steady supply of electrical power from the alternator, the constant power usage from your vehicle’s accessories (headlights, power seats, radio, etc.) will drain your battery.
  • The water pump stops pushing coolant through the engine. If the water pump stops turning, it’s only a matter of minutes before the engine overheats, resulting in potentially catastrophic damage.
  • You’ll lose power steering. Once the power steering pump stops turning, you’ll lose all hydraulic steering assistance. This makes the steering wheel harder to turn, especially at low speeds.
  • Belt fragments can strike and even wrap themselves around the pulleys and other engine components. Needless to say, picking out chunks and strands of old serpentine belt can be time-consuming, not to mention expensive.
  • You’ll risk damaging the belt tensioner. A sudden loss of tension could cause the spring-loaded belt tensioner to snap back violently, which could damage the tensioner internally. A damaged belt tensioner can quickly wear out or otherwise damage any new belt installed afterward.
  • You’ll lose air conditioning. Since the compressor can’t turn without the drive belt, you won’t be able to keep your car’s interior cool.

Spot the Signs Before It Breaks

A new serpentine drive belt is cheap when compared to the potential engine damage that could happen if one breaks. In other words, a little preventive maintenance goes a long way towards stopping belt failure.

One look at your belt can tell you if it needs replacing. Here are a few signs to watch out for:

  • A glazed appearance anywhere on the belt
  • Cracks along the ribbed portion of the belt
  • Frayed or torn edges
  • Visible deformities on the belt itself

You can also tell by ear if your drive belt needs replacing. If the belt squeaks, squeals or makes any other noise upon engine startup or during any other point of engine operation, then it may be time to replace that belt.