What Are the Symptoms of a Bad Fan Clutch?

Cars can get you frustrated at times, especially when you don’t know what’s wrong or how to diagnose the problem. Sometimes, you just have to take the car to a mechanic to look at it. If you are a fan of cars, you should know that fan clutches can fail you at any time.

However, there are several ways to tell whether this vital part of your car will fail or not. This article covers everything you need to know about “What are the symptoms of a bad fan clutch.”

What Is A Fan Clutch?

A fan clutch controls the movement of the car’s engine cooling fan. This allows the fan to run at a certain speed, cooling the engine’s temperature in the process. The fan clutch, in other words, is in charge of transferring energy from the engine fan belt to the fan itself.

What Is A Fan Clutch

Although most modern cars come pre-installed with electric cooling fans, older car models still need their mechanical fan clutch to control the fan blade. Furthermore, the fan clutch comes pre-installed on the water pump or a different belt-driven fan pulley.

However, note that the fan clutch is an essential part of your cooling system. And your vehicle may begin to experience overheating engine issues once they fail.

How To Diagnose A Failing Fan Clutch

The fan clutch controls your cooling fan, and it is an essential part that keeps your car engine cool. Furthermore, these clutches might fail when you least expect, which can be frustrating. However, here are signs you can look out for so you don’t get caught off guard.

How To Diagnose A Failing Fan Clutch

1. Vehicle Overheating

As you already know, the fan clutch controls the cooling fan. And an overheated engine is the first warning sign of a failing fan clutch. Although most drivers know about their engine overheating issues, their attention does not shift to the fan clutches right away.

If you choose to leave this issue unattended, the faulty fan clutch will prevent your cooling fan from operating at optimal efficiency, causing engine overheating and other serious issues in the long run.

2. Insufficient Heat

If you stay in cold regions or areas, then a failing fan clutch may cause serious issues for your car. If the fan clutches fail, this vital part of your car will remain engaged all the time and cool off the engines continuously. This means that instead of the engines overheating, they won’t get enough heat supply.

3. Loose and Wobbling Fan

If you hear a wobbling sound when driving, especially at high speed, then know that your clutches may be breathing their last. You can park your car right away and open the hood to check this out

If the fan feels loose and wobbly when you spin it, then know that it is time to prepare your wallet for a fan clutch replacement. Additionally, if you observe any oil coming from the clutch hub, this is another indicator of a faulty engine fan.

4. Excessively Loud Cooling Fan

Excessively loud cooling fans are another warning sign that your fan clutch is about to fail. Note that your fan will continue to run at their best even if your clutches become jammed. However, this condition may not be safe for your fans to work. And the high-blowing fan may result in an excessively loud engine.

This noisy engine could be present at all times, and it’s most noticeable when the engine is cold or hot. It is, however, better to park your car right away or drive slowly.

5. Decrease in Car Acceleration, Power & Fuel Efficiency

First, check your fan clutch and then the fan itself if you notice that your car isn’t working as it should. Besides loud engines, a decrease in car performance, acceleration, and fuel efficiency is yet another effective way to diagnose a failing fan clutch.

Furthermore, a stuck fan clutch will cause permanent fan damage, excessive drag on the engine, and a drop in car acceleration and fuel efficiency.

How to Properly Check the Fan Clutch?

If you don’t want to spend much money in a car repair shop, you can run a routine check on your clutch fan and see if it needs a replacement. Here’s how to check the health of your fan clutch:

How to Properly Check the Fan Clutch

Spin and Wiggle the Fan

Regardless of what type of fan clutch you have, you should be able to give the clutch a gentle spin. If the fan spins more than three times, you may need to get your fan clutch replaced. However, if the clutch doesn’t spin at all, then it may be due to a faulty bearing.

Furthermore, once you are done checking the fan spin, try to move the fan forward and backward. You may have a worn bearing if you hear or feel the fan clicking.

Check the Clutch for Leaks

Your fan clutch requires the use of heavy silicone oil to function correctly. These oils provide the soft engagement the fan needs to drive properly. If you notice any silicone fluid leaking out of the clutch, note that your clutch is on its way to failing.

Check the fan speed

You should be able to hear the sound of your clutch fan engaging and the rushing of air. You can use an optical tachometer to measure the fan speed. Or you can manually take note of the fan speed as the engine temperature increases. Try to note any sudden changes in the fan speed as the temperature increases.


The fan clutch is an essential part of your car that helps the cooling fan to rotate and keep your car engine cool. A little heat is good for your car engine, but too much of it will create other issues for your car. To prevent your fan clutch from failing you at an ungodly time, you can take several steps to check your clutch’s health.

Overheating vehicles, loud noise, insufficient heat production, and decreased car performance are all symptoms of a failing clutch. You can further inspect your clutch’s health by taking a quick spin at the fan, inspecting the fan speed, and checking for oil leaks.

Once you notice these warning signs, know that it is time to get the clutch fan replaced.

Leave a Comment