An idler pulley in a car guides the serpentine belt, also known as an “accessory belt,” around various parts of the engine, playing a role in the smooth operation of components such as the power steering pump, alternator, water pump and more.
When your idler pulley starts to fail, you might notice these symptoms:
- Chirping noise from the engine
- Issues with electricals, steering or water pump because they are connected by the belt
- Check engine light illuminates as a result of components failing to operate
How much does it cost to replace an idler pulley?
Replacing an idler pulley costs $151 to $320 for parts and labor. Your repair bill might be higher depending on how many idler pulleys your vehicle has and if your mechanic suggests changing all of them at once. You might also want to replace the serpentine belt at the same time, which adds to the cost.
An idler pulley generally costs $100 or less. For example, an idler pulley for a 2015 Ford F-150 with a 5-liter engine costs $105.88 from Ford. Note that there are two similar pulleys on this engine, called tensioner pulleys. Those pulleys can be adjusted to modify belt tension and generally cost more; one costs $119.30, and the other costs $176.72.
You could also shop around for aftermarket replacement parts for a potential cost saving. Take a look at the first three parts from AutoZone and the last one from a retailer of original Ford parts:
| Car | Part | Source | Price ($) |
|---|---|---|---|
| 2006 Ford Focus | Duralast A/C Drive Belt Idler Pulley 231107 | AutoZone | 29.99 |
| 2006 Ford Focus | Duralast Accessory Drive Belt Idler Pulley 231611 | AutoZone | 13.49 |
| 2006 Ford Focus | ACDelco Gold Accessory Drive Belt Idler Pulley 36328 | AutoZone | 51.99 |
| 2006 Ford Focus | Accessory Drive Belt Idler Pulley – Ford (1S7Z-8678-AC) | Ford OEM Parts Direct | 36.80 |
How long does it take to replace an idler pulley?
Replacing an idler pulley takes 20 minutes to nearly an hour. Across the United States, labor rates range from $110 to $175 per hour, meaning the labor costs for your repair can range from $44 for 20 minutes at the lowest rate to $157.50 for nearly an hour at the highest rate.
How to replace an idler pulley?
Replacing an idler pulley is an easy to intermediate task; the labor hours estimates above suggest that a professional with the right setup can do it in less than an hour. Home mechanics should be able to swap out an idler pulley with typical tools. For example, working on a Ford F-150 will require only a socket set, ratchet, possibly a belt-removal tool and requires no lifting of the truck.
Broadly, removal of an idler pulley follows these steps:
- Remove parts that block access to the pulleys – hoses, plastic covers, etc.
- Remove serpentine belt
- Remove pulley
- Install new pulleys
- Reinstall serpentine belt
Should you replace the idler pulley when replacing the serpentine belt?
While there’s no absolute requirement to replace both at once, some mechanics suggest you change the serpentine belt when you change the idler pulley, and vice-versa. However, replacement intervals for idler pulleys tend to coincide with the replacement schedule for a serpentine belt (50,000-100,000 miles), so in those cases, changing both at once is recommended.
Xuyun Zeng is a content strategist with a wide-ranging content background including tech, journalism, cars and health care. After graduating with highest honors in journalism, Xuyun led a newspaper to win eight awards, helped start an award-winning film industry podcast and has written over a hundred articles about cars repair, state laws and insurance. Prior to joining Jerry, Xuyun worked as a freelance SEO consultant with a mission to create the best content that will help readers and grow organic traffic.
Phil Metzger is a personal finance editor and writer with more than 30 years of experience editing and writing content across a variety of industries. In writing and editing for Jerry, Phil’s mission is to help car owners better understand their vehicles and the costs associated with car ownership. Before joining Jerry, Phil worked as a writer and editor for newspapers, magazines, television radio and online news. His work has appeared in many major publications and websites over the years, including a series he edited that was a finalist for a Pulitzer Prize.
