How Long Should the Radiator Fan Run Normally?
3 Answers
The radiator fan activates based on the temperature of the engine coolant. Generally, when the coolant reaches around 100 degrees Celsius, the radiator fan starts operating automatically. Here is some relevant information about the car radiator fan: Definition: The radiator fan, also known as the radiator, is a key component of the car's cooling system. Its function is to dissipate heat. The coolant absorbs heat in the water jacket, flows to the radiator to release the heat, and then returns to the water jacket to circulate, achieving temperature regulation. It is an integral part of the car engine. Working Principle: The radiator is a crucial component of a water-cooled engine. As an essential part of the cooling circuit in a water-cooled engine, it absorbs heat from the engine block, preventing the engine from overheating due to the high specific heat capacity of water.
Last time I was stuck in traffic, the fan ran for a full five minutes, and I was really panicked at the time. Later, I asked an experienced mechanic and learned that this is very common, especially when idling with the AC on in summer. It's completely normal for the fan to keep running to cool things down. The hotter the engine bay gets, the more frequently it runs – I've even seen it run continuously for ten minutes in stop-and-go traffic. As long as the temperature gauge isn't giving any warnings, there's no need to worry. In fact, you should be more concerned if it suddenly goes quiet, as the fan might be stuck, which could really lead to overheating. Here's a little tip: when you park at night, don't turn off the engine immediately; let it run for a while longer to dissipate heat better.
Over the years of working in repair shops, the most intuitive way to gauge how long the fan runs is by feeling the temperature difference between the upper and lower radiator hoses. The normal start-stop temperature points are 84°C to start and 91°C to stop, with the low-speed setting able to drop the temperature by seven or eight degrees. However, when the air conditioning is on, it's a different story—the fan will definitely run as soon as the compressor kicks in. Last time, a car owner complained that the fan kept running for half an hour without stopping. Upon inspection, we found the radiator gaps completely clogged with willow catkins, to the point where the cooling fins were no longer visible. So, the key isn't timing—it's about checking whether the actual cooling efficiency meets the standard.
