Should a Fan Clutch Spin Freely When Cold?

As you drive, your engine heats up, and this temperature increases with speed. As such, the spring expands, and this allows for the engaging of the fan clutch. 

How does a fan clutch work?

It helps to note that the fan clutch comprises several internal components that are integral in its functioning. It has clutch plates as well as a coupling. The latter fills with oil and has a valve that controls the flow of oil between two compartments. One acts as a holding area while the other directs to the clutch. As the valve opens, the oil enters the clutch, and this leads to the fast movement of the fan. When the valve closes, the oil moves back to the holding area, and this leads to slipping in the clutch. Eventually, the movement of the fan slows down. Do you now see how all this comes together?

Arising Issues

Suppose your fan clutch has a problem, there is a high likelihood that it stems from the sensitive spring. Also, it could be that the consistency of the oil as lowered, resulting in added slipping of the clutch. Where this happens, the oil cannot cool the engine as needed, and problems will arise from the same. Additionally, the oil may leak, and the clutch may come loose. In any of these cases, the clutch would not work as it should. There have been cases where fan clutches spin freely when cold, and when this happens, you have a problem in your hands.

Note that there are two kinds of clutches. One operates through thermal variations, such as the one described above. The engagement and disengagement of the same will depend on how fast you drive. The other works through the slipping of the plates. Note that the replacement of the two follows a similar procedure. Thus, regardless of what you have in your car, this article will help you in fixing the problem.

How to diagnose a bad fan clutch

From fan clutch roaring to fan clutch noise, there are many signs you should be on the lookout for in this case. The clutch, though small, plays a vital role in the functioning of your car. It gauges the temperature of the air coming into contact with the radiator and protects the engine. When this component does not work as expected, you can look forward to a myriad of problems. Examples include reduced fuel efficiency, lowered cooling, and added strain on the engine, among others. When these things happen, your car’s efficiency reduces, and so does the joy you get from your investment.

Where you think that this component is not working at its best, you can make a few checks to keep your mind at ease. Below, you will find information on how to test a viscous fan clutch. 

Look out for changes in air temperature

The air passing through the vehicle should feel cool when the AC is working as it should. However, when the clutch is not at its best, the cooling will be minimal. You can test this by switching on air conditioning at the coldest level. You should notice a sharp decrease in warmth within minutes if everything is as it should be. Where the air remains warm and does not cool down, you may have a problem. Start by checking all the vents to ensure that the temperature is the same throughout the car. In some cases, the outlets could be the cause of your concern. It also helps to hold your hand near the vents to feel the changes more than you would when leaning back on your seat.


People often complain of sounds in their cars when their clutches do not work as they should. It is common when facing issues such as fan clutch stuck engaged or fan clutch hard to spin. In this case, air will move through, and owing to the pressure; there will be the creation of a noise that is similar to a roar. You can hear this when inside the vehicle. These noises are common when driving the car at high speed. Thus, the next time you are on the road, increase your speed, and listen to your vehicle. If the noises are loud, you probably have some binding problems which lead to warm air in the cabin. With the fan not turning, this summer will feel longer than it is.

Note the Engagement

When you start your car, it should take about five minutes for the clutch to engage, and you should hear this. After this comes the roar of the fan, designed to give you an enjoyable driving experience. If you turn the car on and the engagement does not take place, you could have a problem. The same also holds when the engagement takes place slowly, or the fan comes to life as soon as you start the car. It helps to pop the hood so that you can hear the engagement take place. You can also use the temperature gauge to tell if there is a problem. Suppose your fan starts working when you hit X temperature. Wait until you hit X then start listening for any engagement. Failure of kicking in will alert you as to the presence of a problem.


The faster you move, the more likely you are to notice problems with the clutch. However, be careful when doing this as other road users require you to drive safely. Accelerate the car and watch how the fan reacts to this. Where the clutch is fine, the cooling rate should reduce to allow the rushing wind to cool the engine. If the fan works at a faster rate, you have a problem.

Manual Inspection

Now that you have listened to your car, the next step lies in inspecting it. Start by parking the car, turning off the engine, and engaging the handbrake. Pop the hood and use a hood strut to keep it open. Ensure that the engine is cool and off before working on the car. Look for the clutch and assess its general condition, looking out for any signs of damage. Next, feel around for any oil leaks to see if the clutch is shot. You will find some traces of oil, and this is perfectly normal. However, heavy oil coatings and streaks are another story. You can now turn the fan by hand and see how much it spins. If it does so with ease, there is a high likelihood that it can spin. If it resists moving a lot, there is a chance that it is bound. In both these cases, a replacement is of the essence.

Having ascertained that your clutch has a problem, the next step lies in fixing it. Below, you will find details on how to fix a bad fan clutch, and the instructions are pretty straightforward. Alternatively, you can head to the garage and get a professional to carry out this task. It will cost you at least one hundred and fifty dollars on average to get the work done. For DIY lovers, proceed to the steps below.

Fixing the Problem

For this process, you will require a rubber mallet, a wrench, a socket set with a ratchet as well as a pulley locking tool. Before you undertake a replacement, you should make sure that there is a need for the same. The clutch should neither be free-wheeling nor resistant to movement.

Start by removing the fan shroud, which should have several bolts holding it down. In some cases, you may need to remove the top radiator hose for you to reach the shroud. In this case, you must drain the coolant system before unfastening anything else.

At this point, you can now access the fan, and there are two ways in which you can do this. Where four bolts attach to the fan, you will require a wrench to perform the removal. The fan could also be in place by way of a large nut. Here, you will need a pulley locking tool to do this. In this way, you can ensure that the pulley will not move as you loosen the nut. For people new to DIY, the pulley locking tool may not be an option. In this case, you can use a screwdriver, which you should position as needed to protect the bolt edges.

Now, move the fan from one side to the other to slide it off the shaft and place it on a safe space. Remove the bolts that attach the clutch to the fan and replace this with the new clutch. Ensure that the bolts running into the holes have their threads lining up as needed. You can now tighten them using a wrench and place the fan in the engine. Make sure that the water pump shaft alignment is as it was when you opened up the compartment. 

Align the bolts such that the threads are in place. Failure to do so will lead to tightening of the bolts in a crooked manner that will lead to problems in the future. Put the fan shroud in its place, keeping up with the aligning as you have done in the previous steps. Where you had taken out the top radiator hose, place it where it was and refill your coolant system. 

In those few and simple steps, you have put your clutch problems to rest. Good job!

Editorial Staff

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