Serpentine Belts, Timing Belts & More

What Does a Serpentine Belt Do?

Most drivers recognize that their vehicles use more than one belt, but it's hard to know what they do and the differences between them. The serpentine belt carries power from the crankshaft to other vital systems like the alternator and air conditioner compressor or the accessory drive belt. These belts tend to wear out after 60,000 to 80,000 miles, but you'll know it's time for a serpentine belt replacement if you start to hear a loud whine or squeak coming from under your hood. This happens when the rubber material of the belt wears down and slips on the metal pulley. Don't ignore the squealing! If your belt fails altogether, it can cause your engine to overheat and stop running entirely.

How to Replace a Serpentine Belt

As part of your routine vehicle maintenance, you should inspect your serpentine belt for cracking or oily residue as this can indicate a coolant or oil leak. When checking or replacing your serpentine belt, ensure you have the proper tools required and make a note of the path the serpentine belt takes as it feeds through each of the components so you can route and tension your new belt correctly. Incorrectly routing or tensioning your belt can cause damage to your engine. Consult the vehicle manual for your Jeep Grand Cherokee or your Subaru Impreza. Don't worry if you're missing the manual for your vehicle; depending on the year, make, and model, several manufacturer websites offer online manuals.

Additionally, while you're checking or replacing your serpentine belt, make sure to check the power steering hoses, heater hoses and radiator hoses for cracks or leaks. NAPA Auto Parts offers hose repair kits, hose adapters, hose clamps and more, so you can make sure your hoses are in good working order.

What Does a Timing Belt Do?

If your vehicle requires gasoline or diesel fuel to run, a carefully orchestrated process of internal combustion begins every time you start your engine. All the components must perform at a precise point in the process or the whole system breaks. Just like a band playing a live concert, if one musician loses the timing, you immediately hear the result!

The pistons of your vehicle are attached to the crankshaft, which must rotate at a particular rate to match the opening and closing of the camshafts, which regulate the intake and exhaust valves. The timing belt is what ties it all together, synchronizing the movements so everything works congruently. If you begin to hear a ticking or clicking coming from under your hood or you notice a misfire, it's a good idea to check the timing belt.

Signs of a Bad Timing Belt

Depending on the vehicle, checking your timing belt is possibly as simple as removing a plastic housing cover to see how the belt is moving when the engine is running. However, chances are the process is a little (or a lot) more involved on other vehicles, so consult your owner's manual to know the situation with which you're working. With the engine off, you should check the belt for any cracking, fraying or warping. Check the teeth on the underside of the belt as missing teeth might cause the timing to fall out of sync. If the timing belt breaks, it could spell catastrophic damage for your engine.

If you notice any of these signs, then the timing is right for a timing belt replacement! NAPA Auto Parts sells timing belt kits, serpentine belt kits, camshaft tools, timing gear locks and more to ensure you get your at-home auto repair done right. If you don't have time to tackle a timing belt replacement, the NAPA Network has your back. Our skilled force of ASE-certified technicians will get your repairs done quickly and correctly at any one of our conveniently located NAPA AutoCare Centers.