What happens when a bad fan clutch goes bad?
When a fan clutch goes bad and causes your vehicle to overheat, it’s usually because the fan clutch is unable to get into its ‘Engaged’ mode. Thankfully this can be tested (indirectly) by manually locking the fan clutch into its Engaged Mode and I’ll show you how in this case study. What Vehicles Can I Apply This Info To?
What’s the difference between standard and heavy duty fan clutches?
Standard-Duty Thermal Fan Clutch: This design turns the fan at 60-70 percent of the water pump shaft speed when engaged, and 20-30 percent when disengaged. It’s made for fans with a lighter pitch. Heavy-Duty Thermal Fan Clutch: This fan style turns the fan at 70-90 percent of the shaft speed when engaged for increased cooling.
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.
When to know if your car fan clutch is binding?
Activity that’s louder than normal may indicate binding. A binding fan clutch will typically be accompanied with warm air flow from the A/C, since the fan isn’t turning the way it should be. Start your vehicle and listen for the fan to engage. Give the engine a little time to warm up. After 4-5 minutes, the fan clutch should come to life.
What happens to the fan when the clutch goes bad?
The cooling fan clutch is part of the cooling system that engages or disengages the fan depending on the engine temperature. It is typically bolted between the water pump pulley and the fan. When a fan clutch goes bad, your fan may run at all times, or it may not run at all.
Is the fan pulley connected to the water pump?
The engine cooling fan, made of plastic or metal, isn’t hard-connected to the fan pulley or water pump, but instead is soft-connected via the fan clutch. A properly-functioning fan clutch is critical to engine reliability, as it works to maintain a safe temperature range.
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.
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.