2016 Ford Focus - Fan Clutch

How Does a Cooling Fan Clutch Work?

Vehicles are often equipped with one of three distinct types of engine cooling fans, one of which is a cooling clutch fan. Older vehicles are more likely to have a clutch-style cooling fan rather than an electric cooling fan that is controlled by a relay. The cooling fan clutch engages or disengages the cooling fan depending on the engine temperature and is typically bolted between the water pump and the fan itself. Cooling fan clutches utilize a silicone-based oil that is sealed in the clutch chamber and bi-metallic springs that are designed to release oil pressure and engage the clutch at the appropriate temperature. This also allows the fan to disengage once temperatures inside the engine compartment have stabilized, and it may also be able to slip against the resistance of air passing through the radiator while driving. This design permits the fan to spin freely, helping the engine to reach operating temperature more quickly and also reduces the load on the engine caused by driving. Fan clutches may also not respond to temperature at all, but might instead be dependent on engine RPM to activate. The fan clutch on your vehicle may suffer damage over time or can simply wear out with age, which might prevent it from operating when and how it should. Symptoms of cooling fan clutch failure include the engine running at a hotter temperature when idling or at lower speeds, or you may notice that the air conditioning performance may also drop due to a lack of airflow through the A/C condenser. Cooling fan clutch failure may also cause the fan to run all the time, or it may fail to run at all. A bad cooling fan clutch can cause overheating, poor gas mileage, excessive noise, slower acceleration, and loss of power due to the added load of a stuck fan clutch on the engine. Thermal fan clutches can often be tested by waiting until the engine reaches operating temperature, shutting off the engine, and attempting to spin the fan by hand. If the fan spins freely at operating temperature, or if it cannot be spun at all when the engine is cold, the fan clutch may have failed and needs to be replaced. Failing to replace a damaged fan clutch or other cooling system parts may lead to overheating, severe engine issues, or damage if not addressed promptly. If you are experiencing these issues check out our articles on how to replace a fan clutch and what causes engine overheating to keep your vehicle running its best. If you determine your fan clutch is no longer working, you can find a replacement cooling fan clutch for your vehicle at O'Reilly Auto Parts.