A fan clutch is one of the unsung heroes that keeps your engine cool and road trips smooth. But if you have a bad one, it can cause everything from an overheated engine to an out-of-control cooling fan.
This Article Contains:
- 4 Common Symptoms of a Bad Fan Clutch
- How to Check a Bad Fan Clutch
- How to Replace a Bad Fan Clutch (Step-By-Step)
- 4 FAQs about Fan Clutches
Keep cool and read on.
4 Common Symptoms of a Bad Fan Clutch
Here are a few tell-tale signs that’ll help you clue into the problem:
1. Engine Overheating
When the fan clutch wears out from years of service or heavy use, it loses its ability to operate the cooling or radiator fan efficiently. As a result, the engine may heat up even at low speeds or stay heated for a long time — leading to engine overheating.
2. Loud Cooling Fans
Do you hear unusual clicking or squealing noises when your engine’s not running or the AC’s on?
It’s usually caused by a clutch shoe stuck in an engaged position, which makes the cooling fan run at full speed — resulting in a loud fan noise.
Additionally, poor wheel bearings and a broken fan clutch blade can also cause loud sounds in the cooling system.
3. Reduced Engine Performance
A stuck fan clutch means your cooling fan will keep spinning with the water pump shaft. That’s because the fan clutch connects the engine fan and water pump shaft. This affects the engine’s performance as it can’t cool down properly. As a result, your car might feel sluggish, accelerate slower, and sip more fuel.
4. Continuous Fan Spins
If your cooling fan keeps 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 due to the fluid leak, it’ll make the radiator fan spin when it shouldn’t.
So how do you check if something is wrong with your fan clutch?
Let’s find out.
How to Check a Bad Fan Clutch
Fan clutches don’t have a set mileage for the part to last. That’s why it’s important to watch out for early signs and check your fan clutches. 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 you have a bad clutch:
- Spin the fan: Most fan clutches need a little push to spin. If the fan easily spins more than three times, you may have a faulty fan clutch. But if the fan doesn’t spin at all, it might have a stuck bearing.
- Wiggle the fan: If the fan clutch wobbles more than a quarter inch when your mechanic moves the fan forward and backward, you might have a worn fan bearing.
- Inspect for leaks: Your fan clutch’s secret weapon is its 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, which your mechanic can audibly detect. They may also use an optical tachometer to measure fan speed. If the fan spins faster or slower than it should, your mechanic might suggest getting a new fan clutch.
- Scan tool: If you have an electronic fan clutch, you can use a scan tool to check for codes like P0526.
Next, let’s find out how a mechanic will replace a bad clutch.
How to Replace a Bad Fan Clutch (Step-By-Step)
While you can repair the fan clutch, in most instances, it’s best to replace it.
Here’s what your mechanic will do:
- Take out the air intake hose, fan shroud, and serpentine belt to access the fan clutch.
- Next, 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 will then separate the fan clutch from the fan by removing the four large bolts that hold the clutch in place.
- Next, 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 and start your car to check for any issues.
Still have some doubts about fan clutches?
Let’s tackle them next.
4 FAQs about Fan Clutches
Here are the answers to some frequently asked fan clutch-related questions:
1. What Does a Fan Clutch Do?
A fan clutch is a thermostatic device that’s responsible for regulating the engine temperature.
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 helps save fuel.
But when the engine heats up, usually at around 180-190°F, the clutch engages the engine fan and cools the engine by about 20°F before disengaging.
2. What Are the Different Types of Fan Clutches?
There are three types of fan clutches:
- Thermal fan clutch: A thermal clutch reacts to the temperature of the air rushing over it from the radiator. For example, when the radiator heats up, the air passing through also becomes hotter. This triggers the internal valve to release silicone fluid, which engages the cooling fan.
- Torque-limiting fan clutch: This non-thermal fan clutch uses the engine speed to control the fan’s speed. The fan clutch fully engages when the engine heats up at idle or low speed and slowly disengages when the engine speed increases. That’s because the silicon fluid can’t transfer energy at high speeds, causing the fan to spin at a low speed or freewheel.
- Electronic fan clutch: Here, the engine control module relies on various sensors 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 too hot.
3. What Causes a Fan Clutch to Fail?
Excessive, abrupt torque can wear out fan clutches along with other vital car components like belts, tensioners, and cooling fans. High torque demand can also wear out the bearings, ultimately affecting your fan clutch.
4. How Much Will a Bad Fan Clutch Replacement Cost?
Depending on your car’s make, model, and type of fan clutch used, you may have to pay around $140 and $400 for fan clutch replacement. The labor charges can cost you around $70-$130, while a new fan clutch and related parts can go as high as $300.
A failing fan clutch can sneak up on you with an overheating engine, sluggish performance, and louder-than-life surprises. However, checking and fixing a bad clutch on your own can be tricky as it involves careful handling of multiple parts.
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 all your repairs.
Contact us to get your fan clutch fixed right away!