Common questions

What happens if your fan clutch goes bad?

What happens if your fan clutch goes bad?

A properly-functioning fan clutch is critical to engine reliability, as it works to maintain a safe temperature range. A failing fan clutch could leave you stranded with expensive repair bills, so pay attention to these symptoms.

What should I do if my car fan won’t turn?

If the fan spins without resistance or is hard to rotate, replace the clutch. Turn on the engine and let it idle. If you have a thermostatic clutch type — look for the thermostatic spring at the front of the clutch — the fan should not turn until the engine reaches operating temperature.

How can you tell when a fan clutch is engaged?

You should be able to audibly detect when the fan clutch engages, with an accompanying rush of air. At idle, as engine temperature increases, a thermal fan clutch will engage at a certain temperature. Torque-limiting fan clutches will disengage at a certain engine speed. Alternatively, an optical tachometer can be used to measure fan speed.

How does a non thermal fan clutch work?

Non-Thermal Fan Clutches. Non-thermal clutches operate solely based on the shaft speed of the water pump. At low and idling speeds, the clutch allows the fan blade to turn at almost a 1:1 ratio.

What happens when you have a bad fan clutch?

A stuck fan clutch will cause excessive, unnecessary drag on the engine, which can cause a drop in power, acceleration, and fuel efficiency, sometimes to a quite noticeable degree. As the fan clutch is one of the main cooling system components, it is very important to the proper operation of the engine.

What makes a fan spin with a cluthc?

With a fan cluthc your fan will rotate constantly regardless. The clutch engages and locks the blade to it so that it spins faster than normal the hotter that it gets. The only time that your fan will not spin is when the motor is off. It is a common misconception that the fan will only spin when the clutch engages. Click to expand…

When to use a heavy duty thermal fan clutch?

Heavy-Duty Thermal Fan Clutch: This fan style turns the fan at 70-90 percent of the shaft speed when engaged for increased cooling. When disengaged, it turns the fan at 25-35 percent. It’s used with deeper-pitch fans (2 1/2″ of pitch), and works well with higher operating rpm.

Why does my car fan spin when the engine is off?

Fan spins after engine shut-down might indicate a weak clutch. Silicone fluid leaking from the fan clutch would cause this problem. When the engine is off, there are a few things you can do to check the fan clutch: Spin the fan. Electronic types might freewheel, but most fan clutches should spin with a little effort.

What is an electric fan clutch?

The fan clutch is a cooling system component that controls the operation of the engine cooling fans. While many newer vehicles now use electric cooling fans to keep the engine cool, many older vehicles used a mechanical fan clutch to control the fans.

What’s the best temperature to test a fan clutch?

Make sure your new fan clutch is the same type as the original. It’s possible to upgrade from a non-thermal clutch to a more efficient thermal model, but not the other way around. Keep your engine temperature below 210 °F (99 °C) while you’re running your tests to prevent it from overheating.

What causes a car fan clutch to go bad?

Insufficient heat in winter is another common problem but caused by the opposite fan clutch failure. If the fan clutch seizes, it remains engaged all the time, cooling off the engine too much. Excess fan noise at high speed is caused by the same problem, a seized fan clutch.

When do you know it’s time to replace the fan clutch?

According to Hayden, here are some signs your fan clutch might need replaced: Fan spins excessively when engine is stopped (three or more times when hot engine is shut off). Poor A/C performance at idle or low vehicle speeds. Fan speed does not increase when engine is hot.

You should be able to audibly detect when the fan clutch engages, with an accompanying rush of air. At idle, as engine temperature increases, a thermal fan clutch will engage at a certain temperature. Torque-limiting fan clutches will disengage at a certain engine speed. Alternatively, an optical tachometer can be used to measure fan speed.

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Ruth Doyle