Polo 6 1.4 2012 model overheat at idle or slow speed. When i drive in traffic it overheats. If I drive fast, it immediately starts to cool down again. I took it to the mechanics, they diagnosed and said its thermostat holder. They changed it and put a new one but the problem is still there. Can someone please help me by telling me whats the problem.
Engine coolant is cooled when air passes through the radiator. Air is passed when the car drives down the road, but when the car is stationary there is no air being passed through the radiator. This is when the radiator fans turn on and draw air through the radiator. The fans are probably not turning on. Some reasons they fail are broken fans, wiring, bad relay, or even temp sensor.