柴油机水温过高通常会造成散热器内冷却液沸腾、柴油机功率下降、润滑油黏度降低、柴油机零部件间摩擦加剧，甚至会导致柴油机拉缸、汽缸垫烧毁等严重故障。

High water temperature of diesel engine will usually cause  boiling coolant in the radiator , the power decreases, the viscosity of the lubricating oil decreases, the friction  increases, and even cause the diesel engine to pull the cylinder and cylinder head gasket burned.

 这里，就说下造成柴油机高温的主要原因，并附带预防改进措施

Below are main reasons for the high temperature of the diesel engine and preventions and improvements. 

一、时间超负荷作业 Overload operation

柴油机长时间超负荷作业，会使其油耗增加、热负荷升高，从而出现水温过高现象。为此，应避免柴油机长时间超负荷作业。

Diesel engine long time overload operation will increase fuel consumption and heat load, resulting in water high temperature.So please avoid long time overloaded operation.

二、冷却液不足  Insufficient coolant

定期检查散热器及膨胀水箱内冷却液存量，液位低时应及时补充。因为柴油机冷却系统中若缺少冷却液，则会影响柴油机散热效果，造成柴油机高温。

Please check the coolant stock in the radiator and expansion tank, and replenish it in time when the liquid level is low. Because  lack of coolant will affect the heat dissipation effect , and resulting in high temperature of the diesel engine.

三、散热装置相互干涉（工程机械）

Heat sinks interfere with each other (construction machinery)

如果液压油散热器与水散热器一前一后放置，当液压油温度偏高时，势必会造成水散热器进风侧冷风温度偏高，影响水散热器散热。对此，应检修液压系统散热情况，降低液压油散热器对柴油机水散热器散热不良的影响。

If the hydraulic oil radiator and the water radiator are placed in tandem, when the temperature of the hydraulic oil is high, the temperature of the cold air on the air inlet side of the water radiator will be high, which will affect the heat dissipation of the water radiator. In this regard, the heat dissipation of the hydraulic system should be overhauled to reduce the influence of the hydraulic oil radiator on the poor heat dissipation of the water radiator of the diesel engine.

四、风扇皮带过松或风扇变形

Fan belt overloose or fan deformation

定期检查柴油机风扇皮带是否松弛及风扇形状是否异常。因为风扇皮带过松，容易造成风扇转速降低，造成散热器不能发挥应有的散热能力，导致柴油机温度过高。此外，风扇变形也会导致散热器的散热能力不能充分发挥。

Please check whether the fan belt is loose and whether the fan shape is abnormal.If the fan belt is too loose, it is easy to cause the fan speed to decrease, causing the radiator cannot play the due heat dissipation capacity,and resulting in excessive diesel engine temperature. In addition, the deformation of the fan will cause the heat dissipation capacity of the radiator to not be fully fulfilled.

五、散热器表面附着杂物

Debris attached to the surface of the radiator

散热器表面附着杂物是最常见的现象，附着的杂物会使散热器散热面积减小，散热器的迎风面积减小，导致散热器的散热能力降低，引起柴油机高温。因此，应定期清理散热器。

The radiator surface attached debris is the most common phenomenon, the attached debris will reduce the radiator cooling area, the windward area of the radiator, resulting in the heat dissipation capacity of the radiator, causing high temperature of diesel engine.Therefore, the radiator should be cleaned regularly.

六、冷却液循环不畅   Poor coolant circulation 

节温器开度不足，会降低柴油机冷却系统大循环的散热能力。如果柴油机高温，可以将节温器放入水中进行加热检查，一般节温器的开启距离为8～10mm。

Insufficient opening of the thermostat will reduce the heat dissipation capacity of the large cycle of the engine cooling system. If the engine is hot, you can put the thermostat in the water for heating inspection. Generally, the opening distance of the thermostat is 8-10mm.

温馨提示:水泵性能不良，则会造成冷却液流量降低，致使柴油机高温。

kindly reminder：Poor performance of the water pump will reduce the coolant flow rate and cause the diesel engine to become hot.

在检查散热器上、下水室时，上、下水室的温差一般在6～12℃，如果偏小，可更换水泵。水垢过多，也会影响散热器内翅片的散热效率，降低冷却液与冷风的导热能力。对此，应定期清洗柴油机冷却系统，同时，避免使用劣质的冷却液，以减少水垢的生成。

In this regard, check the upper and lower water chambers of the radiator. The temperature difference between the upper and lower water chambers is generally 6-12°C. If it is too small, the water pump can be replaced.Too much scale will also affect the heat dissipation efficiency of the fins in the radiator and reduce the thermal conductivity of the coolant and the cold air. In this regard, the diesel engine cooling system should be cleaned regularly, and at the same time, avoid using inferior coolant to reduce the generation of scale.