When stationary or moving slowly, most vehicles rely on a radiator fan to protect the engine from overheating. The fan comes in many different types, which makes finding the best for your vehicle difficulty. In this article, we make shopping for a car radiator cooling fan easy. The article covers every detail about the fan; how it works, the different types, and more.
Learn everything about automotive Radiator Cooling Fans
What does a Radiator Cooling Fan do?
A radiator fan is the device that moves air through the radiator core to cause a cooling effect. When the engine is running, it produces a lot of heat. The heat can exceed the temperature levels of the engine if unchecked. If that happened, several components would get damaged, most of them permanently. An overheated engine could also ruin the radiator.
To prevent overheating, automotive engines circulate a fluid called coolant in channels running around the engine body. These channels end up in the radiator where they flow in a core and through fine tubes. As you drive along, air enters through the grille, reaching the radiator core and helping to cool the tubes and the coolant inside them.
The airflow when the vehicle is moving at a speed higher than 25 mph is usually enough to cool the engine. At engine idle or below 25 mph, the flow of air drops considerably and the coolant does not lose heat effectively. Running the engine then risks raising its temperature to dangerous levels.
Radiator cooling fans help to increase the rate of cooling by moving more air into the radiator. The fan mounts just behind the grille, in front the radiator or behind it. The radiator can be electric or mechanical, depending on your car’s make or year of manufacture.
Some fans are mounted with a structure called shroud. The shroud helps to increase their efficiency in cooling the radiator and, therefore, the engine. Vehicle radiators are usually installed as a single unit. In demanding applications, two electric fans are often mounted. The setup has its advantages, as we will see later.
Types of Radiator Cooling Fans
Car radiator fans are classified into two main types: Mechanical and electric. The electric radiator cooling fan is the most common today and comes in many different configurations. How do the two fan types differ? Here is a look at each.
Mechanical Radiator Cooling Fan
Mechanical radiator cooling fans run off the engine and use a setup of pulleys and belts to connect to the crankshaft. The mechanical fan must only come on when needed, such as when the engine is idling. To enable that, a clutch mechanism ensures it stops spinning at 25mph or higher.
Most mechanical fans incorporate a thermostatic clutch. The clutch disengages the fan when engine temperature lowers to prevent overcooling. Mechanical radiator fans are a dated technology. As a result, they are rarely used in lately produced vehicles. They are still popular with classic models and available on the auto parts market.
Electric Radiator Cooling Fan
Electric radiator cooling fans run independent of the engine. Instead, the vehicle’s electric system powers them. The fans are equipped with 12-volt motors and a control system comprising sensors and control module. The radiator cooling fan controller contains the electronics to operate the device using signals from the sensors.
Because electric radiator fans use electronic controllers, they can be set to start spinning at specific temperature levels. That ensures they only cool the engine when necessary, such as below 25mph. The control system also often incorporates a thermostat to prevent the fan from overcooling the engine.
There are two versions of the electric radiator cooling fan: push or pull. A push fan is mounted between the grille and radiator core. It works by pushing air through the radiator. Because of its location, the pusher type of radiator fan creates obstruction and does not provide efficient airflow.
The puller type of radiator cooling radiator is mounted in the space between the radiator and the engine. It operates by pulling air through the radiator, unlike the push type, and does not come in the way of the airflow. This masked it more effective than the pusher fan type.
The puller type of fan is the better type, no doubt. However, the decision to have a cooling fan in front or behind radiator assemblies depends on the availability of space. In some vehicles, there’s usually not enough room to install the fan between the engine and radiator.
Electrical Radiator Cooling Fan Vs. Mechanical Fan
Car owners have the choice of either mechanical or electric radiator cooling fan. Mechanical fans, as already indicated, run off the crankshaft while electric types depend on the car battery for power. To help you make a sound decision, here is a comparison of the two types of fans.
Mechanical radiator fans use engine power and may contribute to reduced fuel economy. Because they depend on the engine rpm to run, these fan types may not move enough air when the engine is idling. The mechanical fan takes a lot of space under the hood, compared to the compact electric types that do not connect to belts.
Electric radiator cooling fans are more compact and do not require a lot of space to install. As a result, it’s common to find two fans installed to offer more cooling capabilities. They are also more controllable and can be made to switch on when needed. Electric fans move a constant amount of air, even during engine idle, and cool the engine more efficiently.
Radiator Cooling Fan Design and Specifications
A radiator cooling fan consists of shroud and fan blades. And if electric, an electric motor. The fans are always almost identical, except in the shape and number of blades. More blades mean better airflow. It’s recommended that you ensure four or more. The blades can also be straight or curved.
Straight radiator cooling fan blades are able to move more air than the curved types. However, they produce more noise. Curved blades are quieter, but less powerful when it comes to airflow.
In some applications, the radiator cooling fan making noise is more tolerable than a weak flow of air. Radiator cooling fans come with different specifications. These are what determine how a particular fan performs or even how efficiently it operates. The specs are:
CFM stands for cubic feet per minute and means the amount of air the fan is capable of moving. The higher the CFM rating, the more powerful the fan and the better the cooling performance. The choice of CFM rating depends on the application and engine modifications.
It’s also called the radiator cooling fan and draw rating. It refers to the power rating of the fans motor. Just like the CFM specification, a higher rating means a more powerful fan. The rating should match the vehicle and application, though.
Static pressure means the level of air resistance or the maximum amount of air that the fan is cable of before for a specific CFM. The specification is usually higher at lower CFM and lower at lower amp draw. This spec is not always available as some manufacturers do not indicate it.
How to Choose the Best Radiator Cooling Fan
When looking for a replacement cooling fan for your engine, you want the best type for your vehicle make and application. But finding such a fan can be an uphill task judging by the many types of the device in today’s auto parts market. Here is a look at the considerations to help you find the right fan.
Mechanical or Electric
First, you need to decide whether you need a mechanical or electric fan. Many new cars today use electric radiator fans. They are more controllable since they operate using the component called a module. The radiator cooling fan control module allows the fan to accept the input of sensors, making it more versatile. You can also install the electric fan in tight spaces.
Push or Pull Type
The puller radiator fan is more effective at cooling the radiator core. However, you can only choose it if you have enough space between the radiator and engine to install it. You should never mount a radiator cooling fan where it makes or almost makes contact with other components.
Curved or Straight Blades
Always go for straight blades if your engine produces a lot of heat, especially it uses a turbocharger. Straight blade fans more a larger amount of air and cool the radiator more quickly. In engines that are not likely to overheat, curved blades would suffice.
Shrouded or Without Shroud
Some radiator cooling fans come with an integrated shroud. These are easier to install. They also offer efficient airflow due to the action of the shroud. You can also choose a fan that comes with no shroud and have to install it later.
Small or Large Size
Size matters when it comes to the effectiveness of the radiator cooling fan. We recommend that you choose a fan size that covers the maximum area of the radiator core. You want every part covered so that cooling happens faster.
OEM or Aftermarket
An OEM radiator fan is a perfect fit for your vehicle type and application. However, it offers no options to upgrade, especially if you have modified your engine. They are also more costly compared to aftermarket fans.
Other considerations include the number of blade, CFM rating, and current draw. Choose more blades than fewer for a powerful flow of cooling air. A high CFM rating means more air. Depending on the requirements of your engine, go for the right rating for the specification. The amp draw rating too. A higher value means a more powerful fan.
Radiator Cooling Fan FAQs
Q1. What is a radiator cooling fan shroud?
A. The shroud is the structure that surrounds the fan and holds it in place. It’s usually funnel-shaped and made from plastic. The function of the shroud is to direct air and ensure efficiency. It also prevents air from recirculating and reducing the effectiveness of the cooling fan. Radiator fan shrouds are either one-piece or two-piece components. They may also come integrated with the fan assembly to make a single unit or exist separately.
Q2. What is a radiator cooling fan clutch?
A. It’s the component that engages and disengages the cooling fan so it operates when needed. Radiator fan clutches are two types; thermal and non-thermal. A thermal clutch, as the name suggests, uses the temperature changes to operate. Over time, radiator fan clutches wear down and develop problems, leading to fan issues.
Q3. Why is my radiator cooling fan so loud?
A. One of the most common reasons for a noisy radiator cooling fan is its design. Fans that use a mechanical clutch are generally loud, especially when the clutch is worn. If the fan blades are straight instead of curved, the device will also be loud or noisy. Other reasons include a worn motor or damaged bearings. It’s essential that you have the fan checked if it starts to produce unusual sounds of noise.
Q4. What can cause a radiator fan to stop working?
A. Radiator fans often fail due to the following.
- Damaged blades. They may be cracked, broken, or displaced. Although rare, it does happen and causes reduced cooling rate of the engine.
- Bad wiring. These cause the fan to develop problems and stop working as it should. It could be loose connections, corroded connectors, shorts, and related issues
- Failed sensors. Failing sensors send the wrong signal to the control module. Sensors detect temperature changes, among other conditions that the fan uses to operate.
- Broken bearing. Radiator fan bearings ensure proper rotation of the fan. A problem in the bearing affects the proper function of the fan and may cause it to develop a wobble.
- Bad relay. A bad radiator cooling fan relay causes the motor to fail. This is an electrical problem that can be confirmed by tests.
- Broken clutch or thermostat. It causes problems with starting and stopping of the fan as required. The radiator fan clutch helps to protect the engine from overheating or overcooking.
- Blown fuse. It leads to motor failure and the radiator cooling fan not working at all. The fuse can also fall off. It’s one of the easy to replace.
- Worn or burnt motor. The motor is the heart of the fan. If worn or damaged, it can mean problems with the entire fan assembly
Q5. Can you repair a radiator fan?
A. Radiator cooling fan repair is possible for some firms of damage but not all. A damaged relay or blown fuse, for example, can be replaced. Bad connections or loose connectors are fixable, too. Larger components such as the motor can also be changed. In most cases, the entire assembly consisting of blades, motor, and thermostat or clutch will need replacing.
Q6. What happens when the radiator cooling fan is not working?
A. You will see signs of failure, which are either visible on the fan itself or when the engine is running. The symptoms of bad radiator fan include:
- Increased engine temperature
- Radiator leaking coolant
- Fan making a clicking noise
- Motor not running
- Damaged blades
Q7. What is the cost to buy a new radiator cooling fan?
A. Most fans cost between $300 and $500. The price depends on many factors such as the type of fan, the features it comes with, specifications, and brand. The cost of a mechanical fan is different from the electric type. There’s also the large and small radiator cooling fan, which carry different price tags or fans with higher CFM and amp draw.
Q8. Can you drive with a bad radiator cooling fan?
A. You could. However, you should not attempt to do so. The radiator fan plays an important role in ensuring the engine does not overheat. Without a working fan, you risk ending up with damaged engine parts and expensive repairs or replacements. It’s safer to fix a broken radiator before taking the car out on the road. And if it needs replacing, install a new one.
Q9. How much is the cost to replace a car radiator cooling fan?
A. Most mechanics charge around $100 to change your old fan and install a new one. The amount could be higher depending on your type of vehicle and region. Most radiator fans cost between $300 and $500. Adding that to the labor charges, you can expect the replacement cost to be in the range of $400 to $600.
Q10. Can I replace a radiator fan myself?
A. Radiator cooling fan installation is better done by a mechanic. There are various components to attach and different configurations of the fan. A mechanic will also have the tools and expertise to test components such as radiator cooling fan motor relay, fuse, and electrical connections. If considering taking the DIY route, ensure you have everything that’s needed for the task including knowledge about how to replace the fan.
Your engine is one of the most expensive parts of your car as well as the most important. As such, you want to protect it from damage by any means. The radiator cooling fan does that perfectly by helping to remove heat from the coolant fluid. But that only happens for as losing as the fan is working correctly. This guide aims to help you ensure a functional radiator cooling fan at all times. It will also assist you in the search for a replacement fan from among the many on the market.