What are the symptoms of a faulty fan clutch?
2 Answers
The symptoms of a faulty fan clutch mainly include high engine temperature and poor heat dissipation. This is because the clutch still rotates at low speed when the temperature is high, preventing the radiator from effectively dissipating heat, which naturally leads to higher temperatures. You can determine this through the following methods: 1. After turning off the engine, try to rotate the fan by hand. If it doesn't turn smoothly, this is normal and indicates that the fan clutch is still working properly, as the engine temperature remains high at this time. 2. When the engine is cold, rotating the fan should be very easy, which is normal. The clutch contains a type of oil that expands with heat and contracts with cold. When starting a cold engine, this oil occupies less space, resulting in weaker coupling between the fan and the clutch, so the fan rotates more slowly, allowing the water temperature to rise quickly. Conversely, when the engine is hot, the oil expands, increasing the coupling force and making the fan rotate faster to improve heat dissipation.
I remember the symptoms of a failed fan clutch were quite obvious. The engine temperature would rise very quickly while driving, and the temperature warning light on the dashboard would frequently come on, especially during traffic jams or low-speed driving. The fan noise would become unusually loud, buzzing like a tractor, or there might be no sound at all. This could lead to cooling system failure, causing the engine to overheat easily, potentially resulting in cylinder head damage or harm to other components like the water pump or radiator. I experienced this once—driving in summer, I almost broke down halfway before finding out it was due to internal silicone oil leakage in the clutch, which lost its ability to regulate fan speed. It's advisable to regularly check coolant levels and fan operation, and have it tested or replaced at a professional shop if necessary.