The sewer pipe of the car is not hot, but the upper pipe is hot! The water temperature is high, what's the matter?

1, there are two possibilities: a, the thermostat is damaged and cannot be opened; B, the cooling system has air resistance, and the coolant circulation is not smooth.

2. Working principle:

? As shown in the figure:

Working principle: The heat dissipation of automobile is a mixture of air cooling and water cooling. Engine heat dissipation brings engine heat to radiator through coolant, while natural wind and fan wind take away tropical heat of radiator. Two circulation modes: one is small circulation, the cooling liquid only circulates inside the engine, which has poor heat dissipation effect, but it can warm up the engine as soon as possible to ensure the normal working temperature of the engine; In the second big cycle, the coolant will circulate through the water tank (radiator), and it can be dissipated by natural wind and wind generated by the fan, which has a quick cooling effect.

3. A. The thermostat is damaged, which will cause the engine cooling system to fail to circulate, so the engine temperature will be very high. Solution: replace the thermostat; B, cooling system due to air resistance, resulting in poor engine coolant circulation, leading to engine temperature rise. Solution: Vent the air in the cooling system.