5 Bad Radiator Fan Symptoms & Replacement Cost

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bad radiator fan symptoms

Radiator fan assemblies play a significant role in the overall function of the cooling system. This article will discuss some of the most common symptoms of a bad radiator fan and how to replace it if necessary. We will also take a look at some of the replacement costs associated with this type of repair.

Some signs of a bad radiator fan include unusual noises coming from the engine area, the check engine light coming on, and the engine running hotter than normal. If you notice any of these symptoms, be sure to take your car to a mechanic so they can diagnose the problem.

What is a Radiator Cooling Fan?

A radiator cooling fan is a mechanical device that helps to cool down a vehicle’s engine by drawing air through the radiator. The function of the fan is to circulate the airflow and help in dissipating the heat from the engine.

The radiator cooling fan is usually controlled by a thermostat which turns it on when the engine temperature reaches a certain level. The fan continues to run until the engine has cooled down to the required temperature.

How Do Radiator Cooling Fans Work?

An internal combustion engine produces a lot of heat during operation. In order for the engine to continue running smoothly, that heat needs to be dissipated. For this purpose, the coolant mixture circles around the water jacket in the engine block. The circulating coolant absorbs heat from the engine block and transfers it to the radiator.

The radiator is a large, finned metal device. The fins help increase the radiator’s surface area, which helps dissipate heat more effectively. The hot coolant mixture flows into the radiator at the top. It then flows down through a series of tubes. As it flows, the coolant mixture gives off its heat to the surrounding air. This cooled coolant mixture flows back into the engine block to absorb more heat.

The real problem arises when the car is idling. During this time, the engine still produces a lot of heat, but the car isn’t moving. This means there isn’t enough airflow passing through the radiator to dissipate all the heat. That’s where the radiator cooling fan comes in.

In order to further improve the efficiency of heat dissipation, most modern vehicles are equipped with one or more electric cooling fans. The cooling fan is mounted on the front side of the radiator. When the engine is running, and the coolant mixture is getting hot, the cooling fan comes on and blows air through the radiator. A radiator fan pulls air, and this forced airflow helps dissipate heat more quickly.

It’s important to note that the cooling fan doesn’t actually cool the coolant mixture. Rather, it helps to dissipate heat more quickly. The coolant mixture is cooled by circulating it through the engine block and the radiator.

Where are Radiator Fans Located?

Radiator fans are usually located in front of the radiator, mounted on the side facing the engine. In some cases, there may be more than one fan, with one mounted on each side of the radiator.

Bad Radiator Fan Symptoms

Several symptoms can indicate a problem with the radiator fan. The most common symptoms are:

  1. Engine Overheating
  2. Check Engine Light
  3. Poor Air Conditioning
  4. Blown Radiator Fan Fuse
  5. Whirring Noise

Let us see these symptoms in a bit detail:

1. Engine Overheating:

One of the most common signs of a bad radiator fan is engine overheating. If the fan is not working properly, it will not be able to draw enough air through the radiator. This will cause the coolant mixture to overheat. As a result, the engine will run hotter than normal and may eventually overheat.

2. Check Engine Light:

Another symptom of a problem with the radiator fan is the check engine light. This light may come on for several reasons, but if the radiator fan is not working properly, it will trigger the check engine light.

3. Poor Air Conditioning:

Another symptom of a problem with the radiator fan is poor air conditioning. It is possible for the failure of a radiator cooling fan to cause poor AC performance. In some cases, the fan may not be able to move enough air through the radiator to keep it cool, causing the engine to overheat.

This can lead to a loss of power and decreased fuel efficiency. Additionally, the fan may also be unable to properly circulate air through the condenser, which can prevent the AC system from functioning properly.

4. Blown Radiator Fan Fuse:

The blown radiator fan fuse could be a sign of a failed radiator cooling fan. If the fuse is blown, it may indicate that the fan is drawing too much power and is overheating. This could cause the fan to fail and potentially overheat your engine.

5. Whirring Noise:

If you notice a whirring noise coming from the engine compartment, it could be a sign of a problem with the radiator fan. The fan may be loose or damaged and cause noise. Additionally, the bearings in the fan may be worn out, causing it to make noise.

Causes of Bad Radiator Fan

Let us analyze the most common things that may cause a bad radiator cooling fan:

1. Faulty Radiator Cooling Fan Motor:

A faulty cooling fan motor can cause your radiator fan not to work properly. If your radiator fan is not working, it may be because the motor is not getting enough power or because the motor is burned out. You should check the fan motor’s power supply and ensure it is getting enough power. You should also check the fan motor connections and ensure they are tight and secure. If the problem persists, you may need to replace the fan motor.

2. Clogged Blades:

Another common cause of a bad radiator fan is clogged fan blades. If the cooling fan blades are clogged with dirt or debris, they will not be able to move enough air. This can cause your engine to overheat. It would be best if you cleaned the blades regularly to prevent this problem from occurring.

Additionally, you should check the blade periodically to make sure that it is not bent or damaged. If the blade is bent, it will not be able to move properly and will need to be replaced.

3. Faulty Water Pump:

A faulty water pump can cause radiator fan problems. The water pump is responsible for circulating coolant through the engine; if it fails, the engine can overheat. This can cause the radiator fans to work overtime to keep the engine cool, which can lead to problems.

4. Faulty Thermostat Valve:

A faulty thermostat valve can cause radiator fan problems. If the valve is not functioning properly, it can cause the radiator fan to run constantly or not come on at all. This can lead to overheating and engine damage. The best way to fix this problem is to replace the thermostat valve with a new one.

5. Faulty Relay Switch:

A faulty relay can certainly cause radiator fan problems. If the relay is not functioning properly, it may not provide the necessary power to the fan, which can lead to the fan not running at full capacity or not running at all.

How to Test a Bad Cooling Fan?

Testing your cooling fan is a relatively simple process that can be done with a few tools. Follow the steps below to test your cooling fan and diagnose any problems.

  • Park your car in a safe place and turn off the engine. Let the car cool down for at least 30 minutes before starting the test.
  • Pop the hood of your car and locate the cooling fan. The fan is usually located near the radiator.
  • Find the fuse box under the hood and locate the fuse for the cooling fan.
  • Pull out the fuse and check to see if it is blown. If it is, replace it with a new one.
  • Start the engine and let it idle for a few minutes. The cooling fan should come on and start circulating air.
  • If it does not, the fan motor may be bad and need to be replaced.
  • Please turn off the engine and wait for it to cool down. Locate the two wires that power the cooling fan.
  • Use a multimeter to test for power at these wires. If there is no power, the problem is likely a blown fuse or a bad relay.

How to Replace a Bad Radiator Fan?

Here are detailed guidelines to replace a bad radiator cooling fan in your car:

  1. Park your car on a level surface and turn off the engine.
  2. Lift the hood of your car and locate the radiator cooling fan. It is usually located in front of the radiator.
  3. Disconnect the negative battery cable from the battery terminal using a wrench.
  4. Disconnect the electrical connector from the cooling fan motor using a flathead screwdriver or your fingers.
  5. Remove the bolts holding the fan shroud in place.
  6. Remove the bolts that secure the fan to the radiator using a wrench and pull out the old fan assembly.
  7. Installation is simply the reverse of removal.
  8. Make sure to torque all bolts to specifications listed in your vehicle’s repair manual before reconnecting the negative battery cable to the battery terminal.

Replacing a bad radiator fan is a relatively easy repair that you can do with some basic tools. Follow the steps above, and you will install your new cooling fan in no time!

Radiator Fan Replacement Costs

Radiator fan replacement cost will vary depending on your car and the job’s complexity. On average, you can expect to pay between $100 and $200 for labor. For cooling fan assembly, you will need to budget between $250 and $550.

Hence, the total cost of replacement would come to somewhere between $350 and $750. However, this repair is not very difficult, so if you have some basic mechanical skills, you may be able to do it yourself and save on labor costs.


Radiator cooling fans are a vital part of any vehicle, as they help to keep the engine cool and prevent overheating. Air flows through the radiator cooling fans as your car moves down the road. If the radiator cooling fans are not working properly, it can cause the engine to overheat, leading to severe damage.

To avoid such problems, it is essential to make sure that your radiator cooling fans are in good working condition. If you notice that your fans are not working as well as they should, it is important to have them checked out by a professional.

Frequently Asked Questions

What happens if the radiator fan fails?

If the radiator fan fails, it can cause the engine to overheat. The engine may also run hotter than normal, leading to premature wear and tear on the engine components. In extreme cases, the engine may even seize up and fail.

If you notice that your car’s engine is running hot, or if the temperature gauge is reading higher than normal, be sure to check the radiator fan to see if it is working properly. If it is not, replace it as soon as possible to avoid any serious damage to your engine.

How long can you drive with bad radiator fan symptoms?

If your car has bad radiator fan symptoms, you should take it to a mechanic as soon as possible. Depending on the severity of the problem, you may only be able to drive for a short distance before the engine overheats. In some cases, driving with bad radiator fan symptoms can cause permanent damage to your engine.

What does a bad radiator fan sound like?

A bad radiator fan can make various sounds, including grinding, squealing, or clicking. If you hear any unusual noises coming from the engine area, be sure to check the radiator fan to see if it is the source of the noise.

Can a bad radiator fan cause the check engine light to come on?

Yes, a bad radiator fan can cause the check engine light to come on. This is because the engine will run hotter than usual, and the computer will detect this and set a diagnostic trouble code. If you have a check engine light, be sure to have your car checked out by a mechanic to see if the radiator fan is the problem.

How long do radiator fans last?

Radiator fans are designed to last a vehicle’s lifetime, but they may need to be replaced sooner if they become damaged or worn out. Many aftermarket radiator fans are available, so choosing one compatible with your vehicle is important.

Can you drive without a radiator cooling fan?

Yes, you can drive without a radiator cooling fan, but your engine will overheat very quickly, which is not recommended. Without the fan, the engine will overheat and possibly seize up, causing extensive damage. It is much better to have a working cooling fan so that your engine can stay at its proper operating temperature.

When does the radiator fan come on?

The radiator fan comes on when the engine is running, and the coolant temperature reaches a certain point. The fan helps cool the engine by blowing air over the radiator fins. The fan will usually turn off when the engine is turned off or when the coolant temperature drops below a certain point.

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