What May Cause High Coolant Temperature of A Diesel Generator?

Diesel generators are an essential backup power source and they can provide reliable power for extended periods. When using a diesel generator set, you need to pay attention to the cooling water temperature. If the coolant temperature is too high, it may cause problems such as stuck piston, cylinder scoring, decreased engine oil viscosity and reduced generator performance. What may cause the excessively high water temperature of diesel generator?

Reasons for excessively high water temperature of diesel generator set

Clogged radiator

If the surface of radiator is mixed with engine oil, a sludge mixture of oil and dust can block the radiator and result in difficult to dissipate heat.

Improper use of coolant

Coolant is an important cooling material to reduce the genset temperature and water temperature of the unit. Faulty coolant or a lack thereof will seriously affect the cooling performance and even lead to a rapid rise in temperature. The engine will overheat.

Cooling water pump failure

When the cooling pump fails, it will lead to a small flow of coolant, which greatly reduces the cooling effect. Meanwhile, if there are many scale deposits in the pump, it will also reduce the heat dissipation performance.

Generator overloading

When a diesel generator set is overloaded, the oil supply will increase. This will further increase the heat of the whole machine and exceed the heat dissipation capacity of the unit. It may also lead to black smoke, loud noise and other problems.

Faulty thermostat

A thermostat in the cooling system of diesel generator is essentially a temperature regulator. When the thermostat is opened at about 85 degrees Celsius, it means that the thermostat is in good working condition. It will be fully opened at 105 degrees Celsius and operated at maximum coolant flow. More hot coolant will passe through the radiator, which lowers its temperature by transferring heat to the air. If the thermostat is defective, the high coolant temperature problem may occur.

How to fix the tool high coolant temperature problem for diesel generators?

Check the radiator and the pump

Radiator blockage and scale deposit in the pump are common reasons for too high coolant temperature in diesel generator. Check if the radiator fins are flattened or blocked. If they are flattened, you can use a thin steel sheet to carefully lift the fallen radiator fins back into place and restore their flat shape.‌ If they are blocked, you can use compressed air or a water gun to clean them to restore their heat dissipation effect. If necessary, hot water can be used together with the cleaning solution.

Check if the fans work properly. If the fan belt is loose, adjust or replace it to ensure that the fans can work effectively. If the fan blade is out of shape, correct or replace it. At the same time, it’s also necessary to ensure the cleanliness of the surrounding working environment and regularly clean the scale inside the radiator and the pump.

Use coolant and oil properly

Follow the user manual and generator manufacturer’s recommendations and use the right and high quality coolant and oil. Check the coolant and oil levels and maintain the oil and coolant at the correct levels.

Check the water temperature sensor and water temperature gauge

A faulty gauge can’t activate the cooling system. You can use a surface thermometer to measure the temperature at the water temperature sensor to determine if the coolant temperature is actually too high. If the water temperature gauge indicates something wrong, it may be a false alarm from the sensor or faulty gauge that needs to be calibrated or replaced.

Check the thermostat

A faulty thermostat will fail to keep the correct operating temperature of the entire power generating system. You can try removing the thermostat and heating it in the water container, and then testing its working condition with the water temperature gauge. If the thermostat fails, it should be repaired or replaced.

Reduce the load gradually

If the diesel generator is overloaded, you should reduce the load so that the engine gradually returns to its normal operating temperature.

Contact professional generator maintenance personnel in time

If the above methods cannot solve the problem, you may need to check whether there is a fault inside the engine, such as cylinder gasket damage and improper valve clearance. It is recommended to contact professional maintenance personnel for inspection and maintenance.

At Dingbo Power, we offer a wide range of power generator solutions that reliably cater to the power needs of various commercial and industrial facilities. Our wide diesel generator sets includes Cummins, Perkins, Volvo, Deutz, Yuchai and other engine brands that boast superior quality, performance and reliability. Contact us today for any further information or assistance regarding to electric generating sets.