How do I know if my viscous fan clutch is bad?
To confirm the diagnosis, start with this simple test: Spin the fan as hard as you can on an engine that has not been started that day. If the fan rotates more than five times, you can bet the clutch is bad. You should feel some resistance and the fan may spin up to three times, depending on the ambient temperature.
What happens when fan clutch fails?
Decrease in power, acceleration, and fuel efficiency 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. When it fails, the engine can be put at risk of serious damage due to overheating.
How does a viscous fan clutch work?
How does a viscous fan work? The fan hub is a mechanical coupling that operates based on the ambient temperature. A bi-metallic strip on the outside of the hub heats and cools, and expands or contracts, which opens and closes a valve inside the viscous hub. As it warms up, the fan will kick in to keep the engine cool.
When does a fan cluthc turn on or off?
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…
When to test the Electro Viscous fan clutch?
One of two conditions is possible. If your fan is roaring like a jet engine after it has warmed up, DO NOT TEST. It’s already confirmed that the clutch is locked up and needs to be replaced. Normally, it will roar a little on startup and should quiet down as it warms up.
What causes oil to come out of a fan clutch?
Run your finger along the edges of the bearing seal on the backside of the fan clutch. If it comes away with a heavy coating of oil, the culprit is either a crack or a faulty seal. Radial streaks are another potential clue—this happens when oil escapes from the clutch and is then blown outward in all directions by the fan.
What should I do if my fan clutch fails?
When it fails, the engine can be put at risk of serious damage due to overheating. If your vehicle is displaying any of the symptoms above, or you suspect that your fan clutch may be having an issue, have the vehicle inspected by a professional technician, such as one from YourMechanic, to determine if the car will need a fan clutch replacement.