Signs of Bad or Failing Idler Pulley


The idler pulley is a crucial car component that offers guidance and tension to the engine driving belts. These are directed specifically around several engine accessories, including the alternator, water pump, power steering pump and AC compressor. It offers a smooth point to the engine belt for rotation to reach a certain goal. Most cars have one idler and one tension pulley and in others, you’ll find more than one. Like other car components, these pulleys degrade over time and is generally accompanied by several issues listed as follows:

Which are Some of the Idle Pulley Failure Symptoms?

Which are Some of the Idle Pulley Failure Symptoms?

Pulleys Wear Out Over Time

Wear and tear is the most prominent sign that can be noticed on the pulley. This is because the pulley starts moving against the belt over time, and both components start degrading over time. You would notice marks on the surface of the pulley as it comes in contact with the belt. The pulley and belt degrade to the point that tension starts reducing, and the belt begins to slip.

Squealing Belt

A problematic pulley is generally accompanied by squealing noises that appear from the belt. If the size of the pulley reduces or the entire pulley seizes, it leads to engine belt squealing, which starts rubbing against the surface of the pulley. The issue gets worse as the pulley degrades over time, and idler pulley replacement would help the car run smoothly.

Bearing or Pulley Becomes Damaged

Bearing or Pulley Becomes Damaged

You would notice the bearing or pulley that damages when there is a problem. Over time the breakage becomes so intense that it starts breaking or cracking, and coming apart, or seizing. Due to the torn pulley, even the belt becomes torn or starts falling off the engine. Engine without belt starts overheating or stalling, which impedes the engine accessories’ working.


The bearings present in the pulley makes it hard to spin or freezes it completely. If turning the pulley becomes a complex task, then idler pulley replacement will resolve the issues in no time.

No matter what sort of pulley issue you’re dealing with, consider the idler pulley and belt replacement cost in mind before getting a new pulley to resolve the issues.

How Much Does Idler Pulley Cost?

The average cost of an idler pulley generally falls between $80-$200.The parts cost is separate and charged between $40-$90 & labour costs are generally between $40 and $110. Of course, don’t forget the taxes and other charges levied by the mechanic shops. However, you can save money by getting top-quality car parts and accessories online- the customer’s trusted ‘The Auto Parts Shop‘.

The Bottom Line

Idle pulleys are present in most vehicles, and idle pulley failure symptoms mustn’t be taken lightly. Replacing the problematic pulley with a new one will fix the issues in no time.

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