Bad Radiator Cooling Fan Symptoms
Updated: Feb 1
✔ This article has been fact checked.
A radiator cooling fan plays a crucial role in maintaining the proper temperature of your vehicle's engine and coolant. It is responsible for blowing air through the radiator fins to cool down the hot coolant that is circulating through the engine.
Without a functioning radiator cooling fan, your engine can quickly overheat when stationary or if the ambient air is hot, causing serious damage to the engine and other components.
There are many symptoms of a bad radiator fan, such as unusual noises, the AC not working as it should, the coolant overheating, and the fan coming on when it shouldn't, these are the most common signs.
In this article, we will discuss the signs that a vehicle's radiator fan is faulty, the causes of failure, and the steps you can take to diagnose and fix the problem.
Table of Contents:
What Does the Radiator Cooling Fan Do?
The radiator cooling fan is located in front of the radiator and is responsible for blowing air through the fins of the radiator to dissipate heat from the hot coolant.
As the coolant circulates through the engine, the fluid absorbs heat from the engine. The hot coolant then flows through cooling system and to the radiator where it is cooled down by the fan or the vehicles movement forcing air through the fins.
This process helps to keep the engine at the proper operating temperature, which is crucial for optimal performance and longevity.
What Happens When a Radiator Fan Goes Bad?
When a radiator fan goes bad, it can no longer properly cool the hot coolant flowing through the radiator. This can cause the engine to overheat, which can lead to serious damage to the engine and other components.
In some cases, the fan may not be working at all, while in other cases, it may be working sporadically or making unusual noises.
Sometimes a bad radiator fan can go unnoticed for a long time, especially if you're in a colder climate.
Symptoms of a Bad Radiator Cooling Fan
Below are the most common symptoms of a bad radiator cooling fan. There may be other signs specific to your vehicle not listed below. You may also only notice some of these signs.
1. Radiator Fan Not Working
If the radiator fan is not working, the engine may overheat, especially when idling or driving at low speeds. This can cause the temperature gauge to rise or the coolant temperature warning light to come on.
2. Fan Comes on When It Shouldn't
If the radiator fan comes on when it shouldn't, such as when the engine is cold or when the air conditioning is not on, this could be a sign of a bad fan relay or control module.
3. Blown Radiator Fan Fuse
A blown radiator fan fuse can prevent the fan from working and may be caused by a short circuit or a malfunctioning fan motor.
4. Overheating (High Coolant Temperature)
If the engine is overheating, and the radiator fan is not working or not working properly, this could be a sign of a bad cooling fan.
5. Air Conditioning Not Working Properly
If the air conditioning is not working as well as it used to, this could be a sign of a bad radiator fan, as the radiator fan is responsible for blowing air through the condenser, which is an integral part of the air conditioning system.
6. Unusual Noises (Whirring, Clicking, and Rattling)
If the radiator fan is making unusual noises such as whirring, clicking, or rattling, this could be a sign of a malfunctioning fan motor or worn bearings.
What Are the Symptoms of a Bad Radiator Fan Motor?
A bad radiator fan motor may exhibit similar symptoms to the fan being faulty, such as overheating, the fan not working, and unusual noises. Additionally to these symptoms, a bad fan motor may produce a burning smell or smoke, indicating a failure of the motor.
Is a Cooling Fan the Same as a Radiator Fan?
In most cases, yes, a cooling fan and a radiator fan are the same thing.
A radiator fan is responsible for blowing air through the radiator to cool the hot coolant and also for blowing air through the condenser of the air conditioning system to cool the refrigerant.
Sometimes a vehicle may have a separate air conditioning fan and radiator fan, in most vehicles the AC condenser and radiator use the same cooling fan.
What Causes a Radiator Fan to Fail?
There are several common causes of radiator fan failure, including the following.
faulty fan motor
worn bearings
malfunctioning fan relay or control module
blown fuse
clogged or damaged radiator
faulty coolant temperature sensor
In some cases, the failure may be caused by a problem with the engine's cooling system, such as a leak or a malfunctioning thermostat.
Can I Drive With a Bad Radiator Fan?
It is not recommended to drive with a bad radiator fan, as it can cause the engine to overheat and lead to serious damage.
If you notice any of the symptoms of a bad radiator fan, it is best to have the problem diagnosed and repaired as soon as possible.
How to Test a Radiator Fan
To test a radiator fan, you can use a test light or a digital multimeter to check for power and ground at the fan motor. You can also use a scan tool to check for diagnostic trouble codes (DTCs) related to the cooling fan.
In some cases, a visual inspection of the fan, fan motor, and other components may be necessary.
> Read a more detailed guide on testing a radiator fan
How Much Does It Cost to Fix a Bad Radiator Fan?
The cost to fix a bad radiator fan will vary depending on the cause of the problem and the type of vehicle.
In some cases, a simple repair such as replacing a fuse or a relay may be relatively inexpensive, while in other cases, a new fan motor or a new radiator may be required, which can be more costly.
It is best to have the problem diagnosed by a professional to get a more accurate estimate of the cost of repair.
Conclusion
A radiator cooling fan plays a crucial role in maintaining the proper temperature of your vehicle's engine. It is important to be aware of the symptoms of a bad radiator fan and to have the problem diagnosed and repaired as soon as possible to avoid potential engine damage.
If you notice any of the symptoms such as fan not working, overheating, unusual noises or blown radiator fan fuse, it is best to have the problem diagnosed by a professional to ensure proper repair and prevent further damage.