Serpentine Belt What You Need To Know

You repeatedly hear a squealing, squawking, whistling, and grinding from the front of your car. What’s more, it used to subside but now it’s nearly constant. On top of that, your engine runs hot or may even overheat. Chances are, these symptoms point to a failing serpentine belt.

What is a Serpentine Belt?

So, exactly what is a serpentine belt? Well, it’s actually an innovation from older components known as “V-belts.” Instead of equipping vehicles with multiple belts to power different components, a serpentine belt winds around to supply the function of many belts with just a single belt. While that certainly sounds like a great way to reduce redundancy and to squeeze a bit more efficiency out of the performance, it can create a bad situation.

Most modern cars don’t use old-fashioned V-belts anymore. In the ’70s, as more and more cars were optioned with lots of power-hungry accessories running off the crankshaft pulley, it often became necessary to have as many as four V-belts, each running a different gizmo. There just isn’t room for that many belts and pulleys anymore—not to mention, this belt configuration means that it’s a service nightmare to replace just the inner belt by itself. You’d have to remove the other three first—not a fun job. — Popular Mechanics (

The biggest problem with a single belt powering several different components is that a single belt powers several different components. So, when that one belt goes bad, all those components lose their power and don’t provide their necessary functions. Those components can include the water pump, air conditioning compressor, alternator, power steering pump, air pump, and more.

In one fell swoop, you could find yourself stranded on the side of the road and that’s certainly not an enviable situation.

Signs a Serpentine Belt is going Bad

The good news is, since the serpentine belt is so important, there are signs you can look for to know if a serpentine belt is going bad. Of course, as with any layman’s self-diagnosis, just because you notice one or more of these signs, doesn’t necessarily mean the serpentine belt is the culprit. But in general, the signs a serpentine belt is going bad include:

  • A squealing noise. Listen for a squeal coming from the front of your vehicle. Usually, if a serpentine belt is going bad because it’s loose or misaligned, you’ll hear a squealing sound when the car is running.
  • The power steering goes out. One of the many peripheral components the serpentine belt powers is the power steering. If the power steering isn’t working correctly or isn’t working at all, the serpentine belt might be the reason.
  • The air conditioner doesn’t work. Another system the serpentine belt helps power is the air conditioner. So, if the air conditioner stops working, that’s an indication it’s a faulty serpentine belt.
  • The engine runs hot and overheats. Yet another part the serpentine belt helps run is the water pump. When a water pump stops working, the engine cannot effectively be cooled and the vehicle will run hot. At some point, it will begin to overheat or overheat. Don’t operate a hot running vehicle, because doing so can cause more damage. If your vehicle begins to overheat, come to a safe stop and shut it off immediately.

Until next time, stay safe out there!