Why does the Magotan fan keep running?
4 Answers
The reasons why the Volkswagen Magotan fan keeps running are as follows: 1. Insufficient coolant: Engine overheating caused by insufficient coolant leads to continuous operation of the electric fan. 2. Radiator leakage: Engine overheating caused by radiator leakage, loose or damaged hoses leading to leakage, resulting in continuous operation of the electric fan. 3. Thermostat failure: Due to thermostat issues, the temperature cannot reach the standard level to send water to the radiator, or the water flow is insufficient, causing engine overheating and continuous operation of the electric fan. Note: The fan in the Magotan operates based on signals sent to the computer by water temperature and engine load. The engine computer controls the high and low-speed relays of the fan to regulate its operation, which is also influenced by air conditioning pressure.
There could be several reasons why my Magotan's fan keeps running. Normally, it's reasonable for the fan to continue running for a while after turning off the engine on a hot summer day after a long drive to dissipate heat. However, if it runs for too long, like more than ten minutes without stopping, that's not right. First, check the coolant level to see if it's sufficient, and inspect the radiator for leaks or blockages. If the cooling system's efficiency is low and the engine temperature doesn't drop, the fan has to keep running. A faulty thermostat is also quite common—it controls the opening of the main circulation loop. If it gets stuck in the open position, the engine will think it's always overheating, causing the fan to run continuously. Electrical issues can also be a factor, such as a faulty coolant temperature sensor sending incorrect signals or a stuck relay contact controlling the fan. Another easily overlooked issue is when the radiator's front is clogged with willow catkins or debris, reducing heat dissipation and forcing the fan to work overtime. In such cases, I think it's best not to push it and instead promptly visit a 4S shop or a reliable repair shop for a proper check-up.
When encountering a continuously running fan, I recommend troubleshooting in several steps. A simple initial check is to feel the temperature difference between the upper and lower radiator hoses - if the upper hose is hot while the lower one remains cool, it may indicate a stuck thermostat. Next, observe the coolant flow; bubbling in the hoses or fluctuating coolant levels suggest air has entered the cooling system. Electrical component inspection is also crucial - a faulty coolant temperature sensor can cause the ECU to misread temperatures, while a defective fan controller may directly cause power supply abnormalities. The AC system also interacts with the fan, where excessive pressure during cooling will naturally cause the fan to run at high speed. The Magotan's electric fan has two speed settings - when the low-speed setting fails, the system automatically switches to high speed, making it sound like continuous operation. I've handled many similar cases, with most caused by loose electrical connectors or aged relays.
A continuously running fan is often related to low cooling efficiency. Based on my experience, focus on three key areas: the purity of the coolant—contaminated coolant has poor thermal conductivity, and switching to OEM antifreeze usually solves the issue; check if the radiator fins are clogged with insect debris or dust—try rinsing them with a high-pressure water jet; and inspect the fan motor's carbon brushes for wear, which can cause sticking—if you hear a tractor-like rattling noise, it’s likely a motor issue. Also, prioritize checking the thermostat—a failed rubber seal can disrupt coolant flow, overwhelming the fan.
