How hard should a clutch fan be to turn?
Hear this out loudPauseTo 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. You should feel some resistance and the fan may spin up to three times, depending on the ambient temperature. But even if it rotates three or fewer times the clutch could still be bad.
Should a clutch fan spin freely?
Hear this out loudPauseThe fan should move freely by hand when the vehicle is off. Any strong resistance means its locking up.
How do you tell if your fan clutch is stuck engaged?
Symptoms of a Bad Fan Clutch
- Engine overheating at low speed or when stopped is the most-common fan clutch failure symptom.
- Insufficient heat in winter is another common problem but caused by the opposite fan clutch failure.
- Excess fan noise at high speed is caused by the same problem, a seized fan clutch.
How can you tell when a fan clutch is going bad?
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.
What happens when the fan clutch is activated?
At higher engine bay temperatures, a thermally activated fan clutch will activate, allowing the fan to rotate faster and pull more air through the radiator to provide maximum cooling.
How do you test a fluid coupling fan clutch?
Step 1 With the engine off, inspect the fan blades carefully. Look carefully around the fan clutch for signs of oil leakage. Grab the fan assembly with your hands and move it back and forth. Try to spin the fan with your hands. Turn on the engine and let it idle. Test the fluid-coupling fan clutch visually with the engine running.
How does a torque limiting fan clutch work?
A torque-limiting fan clutch reacts to engine speed. A centrifugal valve opens to allow the flow of heavy silicone fluid, locking the fan blades to the pulley. At idle and low engine speeds, this fan clutch is fully engaged, gradually disengaging as engine speed increases.