Blog Car Care Advice What Does a Fan Belt Do? (+Symptoms of a Bad Fan Belt)
Car Care Advice

What Does a Fan Belt Do? (+Symptoms of a Bad Fan Belt)

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Is your battery light illuminated
Are you hearing weird noises from under your car hood? 
There might be a small animal in there, so check it out. 

No rodents? Good. Then your fan belt might be the culprit. 

Your fan belt, also called a drive belt or V belt, is an essential engine component. A faulty fan belt can cause decreased performance or, worse, cause your vehicle to stall. 

In this article, we’ll discuss what the fan belt does, seven symptoms of a worn-out fan belt, and then answer five fan belt FAQs

This Article Contains:

Let’s buckle up. 

What Does the Fan Belt Do?

Fan belts, or drive belts, connect and power several engine accessory devices such as your air conditioning compressor, alternator, power steering pump, and water pump. These individual belts rotate and generate power when your engine runs.   

However, in modern vehicles, the serpentine belt is usually the only engine drive belt — meaning that it takes over the task of the fan belt as it drives multiple accessory devices. Your engine won’t have both a fan belt and serpentine belt since they perform the same function, but more on that later.  

If you find yourself stuck without A/C on a scorching day or suddenly without power steering, a fan belt could be the culprit, and you should know what signs to look for. 

Want to know what symptoms point to a faulty fan belt? 
Let’s take a look. 

7 Symptoms of a Worn-Out Fan Belt

Here are seven common symptoms of a failing fan belt or V belt: 

1. Noises From Under Your Car Hood

A problematic fan belt will cause unusual noises. Like:

So the noises you hear are because the fan belt interferes with other engine components.  

2. Illuminated Battery Light 

One of the more noticeable symptoms of a bad fan belt, specifically the alternator belt, is an illuminated check battery warning light on your dashboard. A lit battery light can also signal battery problems. However, the alternator belt is usually to blame.

When the alternator belt is faulty, the entire electrical system is at risk of being damaged, and because of this, it will appear as if your battery is defective.

3. Faulty Air Conditioning 

A damaged fan belt may also impact the air conditioner (AC) system, i.e., the air conditioner compressor.

Usually, the air conditioning compressor transfers energy from the AC fan belt to your AC system. But if there are worn-out teeth on your AC belt, the AC compressor may not receive enough power.

So, if your air conditioner is faulty, examine the condition of your air conditioner compressor belt.

4. High Engine Temperature or Overheating

A faulty fan belt could also lead to engine problems, especially if your water pump belt is at fault.

Because your water pump belt works with your water pump to cool down your engine components. Therefore, a damaged water pump belt can affect your water pump and cause your engine to overheat. 

Another thing to remember is that if a fan belt detaches from the engine’s pulley, your engine could end up stalling or dying.

5. Burnt Rubber Smell

Another indication that you should replace your fan belt is a burning odor from your car’s engine bay.

Your internal wires or alternator will emit a burning smell as they degrade because of shorting or irregular currents. This can also happen when a broken or misaligned rubber belt starts to rub against other engine parts — instantly causing the smell of burnt rubber.  

6. Power Steering Isn’t Working

You can also look at your fan belt if your car’s power steering isn’t working. People usually think the steering wheel is a standalone component with nothing to do with the engine. But this isn’t true because it’s part of the power steering system.

Want to know how the power steering system works?
Your power steering connects to the power steering belt. The power steering belt then supplies the energy needed for steering-based vehicle movement.

And if this specific accessory belt cracks or takes on any damage, you can lose the ability to steer.

7. Physical Signs of Wear

You can also inspect and note any signs of wear on your fan belt by:

Once you’ve identified an issue with your fan belt, you should contact a mechanic to diagnose and repair the problem correctly. 

Now let’s move on to some fan belt frequently asked questions.  

5 Fan Belt FAQs

If you’re still feeling uneasy about the fan belt topic, hopefully, the answers to these questions will put your mind at ease. Let’s discuss five fan belt FAQs: 

1. When Should I Go for a Fan Belt Replacement?

A fan belt can usually last between 50,000 and 100,000 miles. 

But the only way to really know when you need a belt replacement is by having your mechanic inspect the old belt.

Fan belts are usually made from a durable rubber compound, but rubber warps over time. This is why it’s crucial you call your mechanic for a belt replacement before you get stuck on the side of the road.

2. Can I Drive With a Broken Fan Belt?

Your vehicle may still run with a broken fan belt, but we strongly recommend that you avoid driving with it. There are a few reasons why driving with a snapped drive belt is a bad idea (we’ll discuss the reasons in the following FAQ.)

If your fan belt breaks while driving, the best course of action will be to pull over as soon as possible and arrange for vehicle towing. Pulling over will keep your engine safe from overheating and taking on unnecessary damage.

3. What Happens When My Fan Belt Breaks?

Since there are individual belts for each component, depending on which belt breaks: 

So it’s a good idea to give each fan belt a check during routine inspections.

4. What Other Belts Are in the Engine?

A. Timing Belts 

The timing belt powers your engine’s camshaft and keeps it synced with the crankshaft.

Your timing belt (or timing chain) times the valvetrain and ensures that your valves open and close at the right time.

B. Serpentine Belt

An older cars engine had many V-belts that powered different parts.

Modern vehicles have a rubber belt called the serpentine belt, accessory belt, or drive belt that snakes through several pulleys.

Note: Your vehicle runs on two main types of pulley systems, i.e., a crankshaft pulley system and your accessory pulleys. With most pulleys, the crankshaft pulley rotates and transfers energy to the rest of the systems via your serpentine belt. 

These ribbed serpentine belts increase the contact surface with the drive and the pulleys (like the tensioner pulley or idler pulley). The ribs help your belt stay in contact with these pulleys and transmit more power.

Your crankshaft makes the serpentine belt spin, powering up engine accessory systems like the:

Put simply, a cars serpentine belt is one belt that powers everything instead of several fan belts for each component. 

5. What is an Automatic Belt Tensioner?

Modern cars have a belt tension device called a belt tensioner (the name is very spot on). The belt tensioner holds the correct amount of tension on the cars serpentine belt so that it can run smoothly.

Most belt tension devices have an internal spring and tensioner pulley maintaining enough force to keep this engine accessory belt tight and prevent it from slipping, squealing, or running hot.

Wrapping Up

Your car’s fan belt system is intricate and connects to many engine parts. Repairs and regular maintenance allows you to avoid possible disaster by catching a problem early.  

Don’t risk driving with a broken serpentine belt or fan belt and causing more damage to your engine. 

Instead, call AutoNation Mobile Service for a drive belt or serpentine belt replacement service. 

AutoNation Mobile Service’s skilled technicians come to your driveway and are available seven days a week. Get in touch and book our services for a fan belt or serpentine belt replacement via our easy-to-use online booking system.