Fan Belt Noise: How to Fix a Squeaking Fan Belt

fan belt noise

Last updated: July 4, 2022 at 14:45 pm

There are a lot of moving parts in a car, and so, annoyingly, sometimes they begin to make bizarre, alarming, and irritating noises. One of the most common causes of car noise is the fan belt. It can often chirp, squeal, and even roar when there is an issue!

The most common fan belt noise issues are bad tension, slipped belt and exposure to coolant. Let’s look at these (and others) in more detail and how to fix them.

What Is a Fan Belt?

The fan belt, also known as the accessory or serpentine belt, is a large moving belt within the car that transports power to engine accessories. Such as the alternator, water pump, AC compressor, and power steering pump.

It has a range of names since older cars used to have multiple belts for multiple purposes, but these have now, in more modern cars, been replaced with one large serpentine belt.

What Happens if There Is an Issue With the Fan Belt?

Typically, your fan belt making noise means that there is issue with it. This can be dangerous and expensive, and it is important to get it looked at quickly.

If your fan belt is worn and snaps, you might find yourself without any steering or power, and if this happens whilst driving it can cause an accident.

Related: 8 Reasons Your Car Is Squeaking When Driving

How Do I Know if My Fan Belt Is the Cause of the Noise?

Of course, with there being so much happening under the bonnet of a car, a noise could be caused by any number of things. If you’re unsure whether it is in fact your fan belt causing the noise in your car there are a few signs that will help.

First, if the noise in your car happens when the engine is on and seems to be coming from the front of your car rather than the back, then it is likely to be the fan belt. Likewise, if the noise gets louder when you suddenly accelerate or turn suddenly this suggests it is the fan belt that is making the noise.

You might also notice that there are other issues within your car since the fan belt is connected to so many accessories. For example, you might have issues with the air conditioning, and you might find that there’s no powered steering. These are all key signs that there is a fault with your fan belt.

What Causes a Fan Belt to Make Noise?

There are many reasons that your fan belt might be squealing, chirping, or roaring. Some of them are more easily fixed than others, and some require you to replace your fan belt entirely.

Cold Weather

If your car is being exposed to harsh temperatures on a regular basis, your fan belt is more likely to dry out. This can then lead to it becoming more fragile and cracked, which will cause a squealing from within your car.

However, if in the winter your car whines or squeals for a while in the morning and then stops, it might not be a sign of a bad fan belt. It is still worth looking beneath the hood, or if you’re not sure what you’re looking at, getting somebody else to.

Exposure to Coolant

Many people use antifreeze in their cars to protect the engine from the ice and coldness during the cooler months.

But unfortunately, antifreeze can be severely detrimental to the fan belt. If so, much as a drop of the highly chemical fluid touches the belt, it can cause serious issues. Even worse, these issues are usually irreparable.

Worn Out or Poorly Aligned Pulley

The way in which the fan belt works relies on a series of pulleys to create the right tension and to

hold the belt in the right position. If a pulley wears over time (which they are likely to do, due to friction), then you will experience a chirping from the front of your car.

Misaligned Belt

If you’ve just had a new belt, put in and it is squeaking, it is highly likely that it is being caused by a poor job. If your mechanic (or yourself) has put the belt in and misaligned it, you’ll have a squeaky fan belt.

Slipped Belt

Sometimes, due to the nature of cars moving at relatively high speeds, the fan belt can slip. This could be caused by insufficient tension or a pulley misalignment. If your fan belt slips, it will cause the pulleys to overheat, and it will begin to cause a high-pitched squeak.

Bad Tension

The fan belt relies on tension to work, and without the correct tension, it won’t run correctly. If the tension is insufficient or too tight, then there will be a noise coming from your fan belt.

Worn or Dry Belt

This is perhaps the most common cause of a noisy fan belt. The belt requires a level of moisture to work correctly and to prevent it from wearing too fast. Without this, it will wear away due to friction.

Even with the right moisture, the belt becomes worn, and therefore they should be replaced every 60,000 to 100,000 miles.

Loose Idler Pulley

The idler pulley is a particular pulley within the fan belt system. It must be strong enough to hold the fan belt in exactly the right place with the right tension as the belt spins.

If it fails to do so, i.e., if it is too loose, then the belt will slip, and noises will begin.

How to Fix a Noisy Fan Belt

Some of the causes of a noisy fan belt can be fixed by retightening or readjusting a bolt here or there. For example, tension issues may simply require a tightening of a bolt on a pulley. However, some issues require a bit more attention.

It is always worth giving your car the right attention that it needs. Otherwise, if you try to do it cheaply or if you try and ‘hack’ your way out of it, you may find yourself paying much more to fix a bigger issue down the line.

Dress the Belt

The fan belt needs moisture to lubricate its movements. Without it, the friction alone would wear belts out substantially quicker. If your belt is squeaking, it might be starting to wear and may need a splash of lubricant to keep it happy. If that’s the case, then you’re in luck!

All you need to do is purchase a belt dressing spray and follow the directions. You will need to apply the dressing spray when the engine is running to ensure that it spreads all the way along the belt and not in just one zone.

Tighten the Belt

As aforementioned, if the issue is tension related, it can usually be easily solved. Try loosening a bolt in the tensioner and moving it whilst holding the fan belt tight. Retighten the bolt and run your engine to see if you’ve correctly fixed the tension.

Replace the Belt

This is the expensive one. If your belt has been subjected to cooler or is cracking and worn, then you must replace it. Not doing so could result in injury.

You can either take your car to a mechanic. Or you can attempt to change the fan belt yourself. It is relatively easy.

To do so, identify where the belt is, and where the necessary pulleys are around it. Loosen the bolt on the tensioner and remove the belt. Check that the tensioner is not also faulty by spinning it around and listening for any grinding noises. If it is all functioning, simply place the new belt in and retighten the tensioner.

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About the Author: AJ

AJ is a self-confessed soundproofing nut. He has written full-time on Quiet Living for the past 3 years, and has a wealth of knowledge about living a quieter life, soundproofing and fixing loud noises.

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