A fan clutch is one of the unsung heroes that keeps your engine cool and the car running smoothly. However, if your car’s fan clutch goes bad, it can cause everything from poor engine performance to an out-of-control cooling fan.
That’s unless you spot and fix it fast!
Keep reading to explore six critical symptoms of a bad fan clutch that can help you diagnose the issue early and the repair cost.
This Article Contains:
- What Does a Fan Clutch Do?
- 6 Bad Fan Clutch Symptoms
- What Are the Different Types of Fan Clutches?
- How to Check a Bad Fan Clutch?
- How to Replace a Bad Fan Clutch?
- How Much Will a Bad Fan Clutch Replacement Cost?
- How Often Should You Replace a Fan Clutch?
But before we discuss the signs of fan clutch failure, let’s quickly understand its function.
What Does a Fan Clutch Do?
A fan clutch is a thermostatic device that regulates the engine temperature.
How?
When the engine is at a normal operating temperature, the fan clutch doesn’t engage and lets the cooling fan freewheel. This warms up the engine quickly and lends a hand in saving fuel.
But in an overheating engine that reaches a temperature of around 180-190°F, the clutch engages the engine fan. Then, it cools the engine by about 20°F before disengaging.
Newer vehicles use the electric fan to prevent the issue of an overheating engine. However, old car models use a mechanical fan clutch to control the fans and keep the engine cool. We’ll go over the different types of fan clutches shortly.
The bigger question is — how do you know your fan clutch has gone bad?
6 Bad Fan Clutch Symptoms
Excessive, abrupt torque can wear out the clutch fan along with vital car components like belts, tensioners, and cooling fans.
Here are a few tell-tale signs to help you spot a failing fan clutch:
1. Engine Overheating
When the fan clutch wears out from years of service or heavy use, it loses its ability to efficiently operate the cooling or radiator fan. As a result, the engine may heat up even at low speeds or stay heated for a long time — leading to engine overheating.
Note: Sometimes, a lack of coolant or a bad radiator can also cause an overheated engine. However, if adding coolant to the radiator doesn’t help, the main issue is with the fan clutch. It’s important to consult a professional auto mechanic to get to the root cause of the problem.
2. Illuminated Check Engine Light
A malfunctioning fan clutch can lead to engine problems, such as a high operating temperature and poor performance. This triggers the powertrain control module (PCM) to turn on the check engine light as a warning.
In vehicles with an electronic fan clutch, the PCM directly controls the clutch and will trigger a check engine light if it notices any anomaly.
3. Wobbling Engine Fan
A failing fan clutch can cause the engine fan to become loose and wobbly. You may hear the subtle noise of the wobbling fan while driving, particularly at high speeds. Additionally, you might also spot fluid or oil leaking from the clutch hub.
To check for a loose fan, cold start the engine with the car parked, open the hood, and observe if the fan wobbles as it runs.
Note: Wobbling fans can also lead to water pump bearing failure. That’s because the fan clutch connects the engine fan to the water pump shaft.
4. Loud Cooling Fans
Do you hear a squealing noise or does the fan spin at full speed when the engine isn’t running?
The squealing fan noise is a major symptom that may be caused by a clutch shoe stuck in an engaged position, which makes the cooling fan run at full speed. This puts extra strain on the fan blade and results in a loud fan noise.
Besides the clutch shoe, faulty bearings or a broken fan clutch blade can cause loud sounds in the cooling system.
5. Reduced Engine Performance
A stuck fan clutch means your cooling fan will keep spinning with the water pump shaft. This may lead to engine damage and affect your vehicle’s performance as it can’t cool down properly. As a result of the fan clutch issue, your car might feel sluggish, accelerate slower, and sip more fuel.
6. Continuous Fan Spinning
If you notice the cooling fan spinning even after the engine is off, you may have a silicon fluid leak.
How does that happen?
Fan clutches contain a silicone fluid that helps control the fan blade. When you have a fan clutch failure because of a fluid leak, the liquid will still be poured out as hot air enters, making the fan spin.
Now, let’s go over the various types of fan clutches and how they work.
What Are the Different Types of Fan Clutches?
Usually, you’ll find these three types of fan clutches on cars:
1. Thermal Fan Clutch
A thermal clutch is a type of mechanical fan clutch. It has a bi-metal thermal spring on the front of the fan that expands or contracts based on the temperature of the air coming from the radiator.
How does it work?
When the radiator heats up, the air passing through it also becomes hotter, causing the thermal spring to expand. This expansion triggers the internal valve to release a thick silicone fluid, which engages the cooling fan.
2. Torque-Limiting Fan Clutch
A torque-limiting or non-thermal fan clutch uses engine speed to control the fan’s speed. This type of mechanical fan clutch fully engages when the engine heats up at idle or low speed.
As the engine speed increases, the clutch slowly disengages. That’s because the silicone fluid can’t transfer energy at high speeds, making the fan spin at a low speed.
Note: When your engine heats up at idle, a thermal fan clutch will engage at a certain temperature. In contrast, torque-limiting fan clutches will engage and disengage at a certain engine speed.
3. Electronic Fan Clutch
Here, the engine control module (ECM) relies on the coolant temperature sensor and oil temperature sensor to ensure the fan clutch operates at the right time. For instance, it might activate the fan clutch when the engine is idling or if it gets filled with hot air.
Next, let’s check out how you can confirm a bad fan clutch.
How to Check a Bad Fan Clutch?
Fan clutches don’t have a set mileage. That’s why it’s important to watch out for early signs of fan clutch failure.
And if you’re not confident with car parts, it’s best to have a professional perform the diagnosis for you.
Here’s how a mechanic will check if your car has a fan clutch issue:
- Spin the fan: With the engine off, your mechanic will try to spin the fan by hand. They should feel a bit of resistance at first. But if the fan spins more than three times, then you have a faulty fan clutch. If the fan doesn’t spin, it might have a stuck bearing. If they notice too much resistance, the clutch may be binding.
- Wiggle the fan: Your mechanic will check if the fan clutch wobbles more than a quarter inch when the fan is moved forward and backward. If it does, you might have a worn-out fan bearing.
- Inspect for leaks: Your fan clutch’s secret weapon is the silicone fluid that powers the fan. If it leaks out, the clutch may lose its strength and wear out.
- Check fan speed: Fan clutches usually engage at a particular engine temperature and with an accompanying rush of air, which your mechanic can detect. They may also use an optical tachometer to measure the fan speed. If the fan spins faster or slower than it should, your mechanic might suggest getting a new fan clutch or electric fan.
- Scan tool: If you have an electronic fan clutch, your mechanic will use a scan tool to check for codes like P0526.
Now, we’ll cover in detail the steps to replace a bad clutch.
How to Replace a Bad Fan Clutch?
While you can repair the fan clutch, it’s best to replace it in most instances.
Here’s what your mechanic or someone with good technical knowledge of the engine compartment will do:
- Take out the air intake hose, fan shroud (a type of covering), and serpentine belt to access the fan clutch.
- Unbolt the fan using a socket wrench.
- Gently rock the fan side to side to slide it off the water pump shaft.
- Place the fan on a table with the fan shaft facing them. They’ll separate the fan clutch from the fan by removing the four large bolts that hold the clutch in place.
- Next, they’ll align the new fan clutch with the bolt holes and gently screw the nuts. They’ll ensure the threading on the bolts properly line up with the nuts.
- Reassemble the remaining parts, like the fan shroud and serpentine belt. Then, start your car to check for any issues.
Wondering how much the replacement process will cost you?
Let’s find out.
How Much Will a Bad Fan Clutch Replacement Cost?
Depending on your car’s make, model, and the type of fan clutch used, you may have to pay around $200 and $545 for fan clutch replacement.
The labor charges can cost you around $99 to $200, while a new fan clutch and replacing related parts can cost you between $100 and $345.
Next, we’ll explore the typical lifespan of a fan clutch.
How Often Should You Replace a Fan Clutch?
A fan clutch generally lasts up to 150,000 miles.
However, it can wear out sooner depending on your driving habits, the climate you live in, and the condition of the cooling system.
Fix Your Fan Clutch Problems with AutoNation Mobile Service
A faulty fan clutch can sneak up on you with a noisy fan, engine damage, and sluggish performance. However, fixing a bad clutch on your own can be tricky as it involves careful handling of multiple parts in the engine compartment.
Instead, you can leave it to the seasoned mechanics at AutoNation Mobile Service.
We are a mobile auto repair service available seven days a week. We offer upfront pricing, convenient online booking, and a 12-month, 12,000-mile warranty on every kind of repair.
Contact us to resolve your fan clutch problems right away!