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Bad Radiator Cooling Fan Signs & Symptoms

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  • 8 min read

Last Updated on: 16th November 2023, 01:49 am

The radiator cooling fan keeps the engine from getting too hot by sending a breeze through the radiator’s heat exchanging parts.

How do you know if your radiator cooling fan has an issue?

There are several clues – you might hear weird sounds, your car’s air conditioner might not cool the air as much, the engine’s coolant might get too hot, or the fan might act like it’s confused, turning on when it shouldn’t.

This air flowing through the radiator cools down the liquid (coolant) that flows around the engine, keeping the engine’s temperature just right.

If this radiator cooling fan is not doing its job well, your engine can get super hot, especially if the car is not moving or if it’s really hot outside. This can be really bad for your engine and even harm other parts of your car.

In this guide, we’re going to talk about how to spot if your car’s radiator cooling fan is having troubles, why it might not be working properly, and what you can do to figure out and fix the issue.

What the Radiator Cooling Fan Does

The fan that cools the radiator sits right before the radiator. Its job is to push air over the thin slices or ‘fins’ of the radiator, getting rid of the heat from the warm coolant.

Coolant is like a liquid heat sponge that soaks up heat as it moves around the engine.

This warm coolant then travels through a series of pipes and reaches the radiator. Here, the fan – along with the air that rushes in when the car is moving – cools it down by blowing air over the fins.

Doing this makes sure that the engine doesn’t get too hot or too cold, but stays just right. This ‘Goldilocks’ temperature is super important for the engine to work its best and last a long time.

car radiator fan

What Happens if a Radiator Fan Goes Bad?

If the radiator fan fails or goes bad, it’s not good at cooling the warm coolant that’s passing through the radiator.

This might make the engine get way too hot, and that’s bad news – it can mess up the engine and other parts.

Sometimes, the fan might completely give up and not work at all. Other times, it might act all weird, like working on and off, or making funny sounds.

A failing radiator fan can fly under the radar for quite a while, especially if you’re in a place where it’s chilly most of the time.

a car being driven in the snow

Bad Radiator Cooling Fan Symptoms

Here’s a list of typical signs that the radiator cooling fan in your car might be having issues. Keep in mind that your car could show other symptoms that are not mentioned here.

Also, you might not experience all of these signs.

1. Fan Doesn’t Spin

When the radiator fan doesn’t spin, the engine can get too hot, especially if you’re in traffic or driving slowly.

You might see the needle on the temperature gauge go up, or a warning light indicating that the coolant is too hot might turn on.

2. Fan Turns On Unexpectedly

If you notice that the radiator fan is turning on at times when it shouldn’t, like when the engine is still cool or when you’re not using the air conditioning.

This might mean there’s something wrong with the fan relay or the part that controls it.

Sometimes the cooling fan can turn on after the vehicle has stopped but this may also be normal for some vehicles.

3. Radiator Fan Fuse Is Burnt Out

If the fuse for the radiator fan is burnt, the fan won’t be able to spin. This can happen if there’s an electrical short or if the fan’s motor isn’t working right.

4. Engine Overheating (Coolant Too Hot)

If your engine is getting too hot and you notice that the radiator fan isn’t spinning or isn’t spinning as it should, this might be a clue that the cooling fan is the problem.

5. Air Conditioning Doesn’t Cool Properly

If the air inside your car isn’t getting as cool as it used to when you turn on the air conditioning, this might be because the radiator fan is having issues.

The fan plays a crucial role in the air conditioning system as it blows air through the part that cools the air (the condenser).

6. Weird Sounds (Humming, Clicks, or Rattling)

If you hear sounds like humming, clicks, or rattling coming from the radiator fan, this might mean that the fan’s motor isn’t working properly or that parts inside the fan are worn out.

a car fuse being removed

Signs of a Bad Radiator Fan Motor

When the radiator fan motor is not in good shape, it can show signs that are like when the fan itself is broken – for example, the engine getting too hot, the fan not spinning, and strange sounds.

On top of these signs, if the motor is bad, you might also smell something burning or see smoke. This would mean the motor has likely gone kaput.

Is a Radiator Fan the Same as a Cooling Fan?

In the majority of instances, the terms “cooling fan” and “radiator fan” refer to the same component in a car.

The job of a radiator fan is to push air through the radiator, helping to chill the hot coolant. It also blows air through the air conditioning’s condenser to lower the temperature of the refrigerant.

However, there are instances where a car might have two different fans – one for the air conditioning and another for the radiator.

But usually, in most cars, the air conditioning condenser and the radiator share a single cooling fan.

Causes of a Radiator Fan to Fail

There are various usual reasons why a radiator fan might stop working properly. These include the following.

  • A broken fan motor
  • Bearings that are old and worn out
  • Fan relay or control module not working right
  • A fuse that has burned out
  • A radiator that’s blocked or has some damage
  • A coolant temperature sensor that’s not working

Sometimes, the issue with the radiator fan can be due to something going wrong with the engine’s cooling system itself, like a leak or a thermostat that’s not functioning as it should.

Driving With a Bad Radiator Fan

Driving with a faulty radiator fan is a bad idea because it can make the engine get too hot, and this can cause major damage.

If you see any signs that the radiator fan isn’t working properly, it’s a good idea to get it checked out and fixed without delay.

car radiator fan

How to Test a Radiator Fan

If you want to check if a radiator fan is working, you can use a test light or a digital multimeter to see if there’s electricity and grounding at the fan’s motor.

Additionally, you can use a scanning device to look for any error codes (DTCs) that are connected to the cooling fan.

Sometimes, you might also need to take a good look at the fan, its motor, and other parts with your eyes to see if there’s anything wrong.

Cost to Fix a Bad Radiator Fan

How much you’ll need to spend to fix a broken radiator fan can change based on what’s causing the issue and what kind of car you have.

Sometimes it can be a simple and cheap fix, like changing a fuse or a relay. But other times, you might need a new fan motor or even a new radiator, which can cost more.

To know how much it’ll really cost to fix, it’s a good idea to let an expert take a look and give you a precise estimate.


The radiator cooling fan is super important in keeping your car’s engine at the right temperature.

Knowing the signs of a broken radiator fan is key, and it’s critical to get it checked and fixed quickly to stop the engine from getting damaged.

If you see any signs like the fan not spinning, the engine getting too hot, weird noises, or a burnt-out fuse for the radiator fan, it’s a smart move to let an expert take a look so it can be fixed the right way and avoid any more damage.

  • Andy Lewin

    Andy Lewin is a senior mechanic, ASE qualified master technician, and an experienced automotive engineer. He's passionate about serving the automotive community with the highest-quality and trustworthy information on all things automotive. He loves to write about car repairs, maintenance, car modifications and tuning, faults, and much more.

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