Serpentine Belt Replacement

How often does the serpentine belt need to be replaced?

Even though automotive manufacturers do not provide any mileage intervals for serpentine belt replacement, they should be changed periodically as part of an overall preventative maintenance plan. Many experts suggest replacement every four or five years or 45,000 to 50,000 miles. Driving in severe climates, especially near the ocean, and extra idling can subtract from these estimates. Belts are made from rubber and over time a belt will stretch, dry out, glaze over and crack.

How serpentine belts work:

Serpentine Belts are designed to transfer the rotational movement of the engine to multiple peripheral accessories in the car. They are relatively inexpensive and easy to change. Belts turn the pulleys for the power steering pump, the alternator and the air conditioner compressor. On many models belts turn the water pump to circulate coolant from the engine to the radiator. While these accessories have very little to do with engine combustion and the power of a car, in many cases the work performed is critical to maintain the engine and to keep it running.

What are the symptoms of a faulty serpentine belt?

A high pitched squeal when starting a car or during a hard turn or when the air conditioning is turned on indicates that a belt may be glazed (shiny on the smooth side) or stretched, and replacement should be planned. Cracking (dry rot) in the grooves – more than one crack per inch – or any fraying along the edges point towards an old belt that has absorbed a lot of heat and needs to be replaced. Lastly, long term contamination of the belt from leaking oil or coolant should be addressed with a new belt.

What can happen is serpentine belt is not replaced in a timely manner?

Not replacing the belts on the engine will result in poor performance and ultimately to the non-performance of a car. A glazed or stretched belt does not travel across the pulleys, instead it slips across with less friction and less turns of the pulley. Water pumps will not circulate coolant as well, leading to a higher running temperature and inefficient engine performance. Alternators will not supply as much electricity which will shorten battery life. Air conditioner compressors will not turn as fast and the interior of the car will not be as cool as expected. A frayed or cracked timing belt will break and all of these accessories will not function: steering will become very difficult, the air conditioner will blow warm air, and the car will run until the stored power of the battery is used up and then it will die.

What is the typical cost to replace a serpentine belt?

  • Estimated part(s) cost = $25-$70
  • Estimated labor cost = $50-$120
  • Estimated total cost = $75-$190

Most automotive service professionals can perform this service. Replacing your serpentine belt is one of the more inexpensive preventative measures you can take to keep your vehicle's health in check. Save time by using Openbay to compare pricing and book an appointment with a shop in your area. Openbay gets back on the road faster, and keeps a little extra in your pocket.

Service article written by an ASE Master Technician