Serpentine Belts: The Unsung Heroes of Car Engines

Serpentine Belts: The Unsung Heroes
of Car Engines

Picture this: You’re cruising down the highway when suddenly, there’s a strange flapping sound coming from under the hood. You pull over to investigate, only to discover the culprit: a damaged serpentine belt. As a vital component of your engine, a faulty serpentine belt can cause all sorts of trouble. In this blog, we’ll dive into everything you need to know about serpentine belts, including how they work, when to replace them, and how to keep them maintained. 

What Does the Serpentine Belt Do?

The serpentine belt is a long, winding belt that’s driven by your car’s engine. They’re typically made of durable rubber and have grooves on one side that fit into pulleys on each of the peripheral devices they power, such as the air conditioning system and the alternator. In some vehicles, the serpentine belt may also power the power steering and power brake pumps, the water pump, and more. 

As the belt rotates, it transfers power from the engine’s crankshaft to the various components it powers using pulleys and a belt tensioner. The belt tensioner is a self-tensioning device that’s designed to maintain the correct amount of tension on the serpentine belt, so it can operate properly. Most belt tensioners have an internal spring and pulley system that keeps the serpentine belt tight and prevents issues like squealing, slipping, or overheating. Over time, the spring can become worn; when this happens, it won’t provide the pressure needed to keep the belt tight.

Serpentine Belt Maintenance and Replacement

Although manufacturers’ recommendations vary, it’s typically recommended to have your serpentine belt inspected once your car reaches 60K miles. Since the belt can lose tension or become damaged before this milestone, periodic visual and audible inspections before 60K miles are also important. 

Most manufacturers recommend replacing the serpentine belt at 90K miles, regardless of its condition to reduce the chances of it breaking. It can be very dangerous if the serpentine breaks while you’re driving—and it can cause severe engine damage. It’s also a good idea to replace the tensioner and idler pulley at that time. To find specific recommendations for your vehicle, check your owner’s manual or ask your service advisor to look it up for you. 

Signs of a Worn Serpentine Belt

If your serpentine belt is damaged or becoming worn, you may notice the following signs:

  • Chirping, squeaking, or squealing sounds coming from under the hood of your car
  • The check engine light or battery light is on
  • The air conditioner isn’t working
  • The power steering isn’t working
  • The engine temperature is high or the engine is overheating
  • An acrid, burnt rubber smell

You can also perform visual inspections of your serpentine belt at home while the engine is off. Here are some signs to look for:

  • Cracks, fraying, or splits on the belt
  • Signs the belt has overheated, such as glazing along the sides
  • Missing chunks or separating layers

If you see coolant or oil on the belt, it’s time to replace it—and get the fluid leaks fixed. 

Schedule an Appointment at EuroCar Service

The serpentine belt is vital for how your vehicle functions. Since it’s not an expensive part, it’s always best to be proactive and replace it before it fails. At EuroCar Service, we offer everything your vehicle needs to stay safe and reliable, including serpentine belt inspections and replacements. We specialize in all European makes, including AudiBMWMercedesLand RoverVolvoVolkswagenSaabFiatJaguarSmart Car, and Mini-Cooper. Contact us today at (206) 527-8828 or request an appointment online.