Back to all

Snake in the Engine (Serpentine Belt)

October 29, 2023

There's a belt that snakes through your engine.  It's even named for a snake, the serpentine belt.  It'll bite you when it breaks, possibly leaving you stranded.  So, it's good to know a little about this snake-like belt.

In early engines, there were lots of belts. They were used to convert the rotating power of the engine to turn a mechanical part.  But engineers had an idea.  Why not consolidate all those belts into one that ran a bunch of different parts simultaneously? Voila!  The serpentine belt.

It's found in the front or side of your engine unlike older belts which were often in a V shape, the serpentine belt has ribs on it which more effectively connect with the pulleys that power the other components.  A serpentine belt may power the water pump, power steering pump, alternator, and the air conditioning: all from one crankshaft. 

Now, all that's fine when everything is working well and the belt is intact.  But when a serpentine belt wears, gets loose, or breaks, it can affect many engine components at once.  Not an ideal situation. 

If you hear squeals coming from the engine compartment, see a battery light, or the engine overheats, those could be signs that your serpentine belt needs replacing.

The good news is that they usually last a long time, from 60,000-100,000 miles or 100,000-160,000 km.  Still, they don't last forever, and your vehicle's manufacturer usually recommends replacing them when they've gone close to the expected maximum.  It’s also recommended that you replace the pulleys and belt tensioner at the same time as they have the same service life. Regular maintenance and inspection of the serpentine belt is not only a good idea; it’s one of those things that you should not let "slip" by.

Tuffy Joliet (South Plainfield)
2031 SR 59
Joliet, Illinois 60586
815-436-1829

More articles from Tuffy Joliet

The Cable Guy (Battery Cables and Maintenance)

March 1, 2026

If you've ever noticed your vehicle's lights are dim or not working at all, the problem could be many things. But one possibility is your battery cables aren't doing their job. A power outage in your vehicle is similar to one in your house and needs to be repaired to get things back to normal. ... More

Ball Joint Replacement

February 22, 2026

Think about this the next time youre driving. Your front wheels can steer your vehicle and, at the same time, the wheels can move, even with all the irregularities in the road moving them up, down and in different directions. Pretty amazing engineering, wouldnt you say? What allows that are part... More

What?s That Yellow Squiggly Line Anyway? (What Warning Lights Mean)

February 15, 2026

You may have noticed when you start your vehicle, youll see several symbols light up on the dash. Theyre different colors and shapes, and sometimes its hard to figure out what each of those symbols mean. They are warning lights and symbolize something in your vehicle is sending you a message. I... More