To extend the service life of diesel generator sets, special attention must be paid to the following winter precautions. 

Only by adhering to these guidelines during daily winter use can the diesel generator set be protected from damage.

Winter Precaution 1: Avoid randomly selecting fuel.

Low winter temperatures reduce the fluidity of diesel fuel, increase its viscosity, and hinder proper atomization. 

This results in poor combustion and degraded performance of the diesel engine in terms of power and fuel economy. 

Therefore, in winter, opt for light diesel fuel with a low freezing point and good ignition performance. Generally, 

the freezing point of the diesel fuel should be 7–10°C below the lowest local temperature for the season.

Winter Precaution 2: Do not use open flames to aid ignition. 

Do not remove the air filter and use a cotton wick soaked in diesel fuel as an ignition aid placed in the intake pipe. 

During startup, unfiltered, dusty air will be directly drawn into the cylinders, causing abnormal wear on components 

such as pistons and cylinders. This can also lead to rough engine operation and damage to the machinery.

Winter Precaution 3: Avoid draining coolant too early or not draining it at all.

Before shutting down the engine, let it idle until the coolant temperature drops below 60°C or until it is no 

longer scalding to the touch. Then, shut off the engine and drain the coolant. Draining the coolant too early 

may cause the engine block to contract suddenly when exposed to cold air, leading to cracks. Ensure all residual 

water in the engine is thoroughly drained to prevent it from freezing and expanding, which could cause the block to crack.

Winter Precaution 4: Avoid using open flames to heat the oil pan.

This can cause the oil in the pan to degrade or even burn, reducing or completely losing its lubricating properties, 

thereby accelerating machine wear. In winter, use low-freezing-point oil. To raise the oil temperature during startup, 

consider using external water bath heating methods.

Winter Precaution 5: Avoid improper startup methods. 

In winter, some operators may attempt to start the diesel generator set quickly by using an unconventional 

method—starting the engine before adding coolant. This practice can cause severe damage to the machinery and 

should be strictly avoided. The correct preheating method is as follows: Cover the radiator with an insulating blanket, 

open the drain valve, and continuously fill the radiator with clean, soft water at 60–70°C. Once the water flowing out 

of the drain valve feels hot to the touch, close the drain valve and fill the radiator with clean, soft water at 90–100°C. 

Then, crank the engine to allow proper pre-lubrication of moving parts before starting.

Winter Precaution 6: Avoid loading the engine while it is still cold.

After starting the diesel generator set, some operators may immediately put it under load. However, when the engine is still cold, 

the oil viscosity is high, making it difficult for the oil to reach the friction surfaces of moving parts. This can lead to severe wear. 

Additionally, components such as plunger springs, valve springs, and injector springs are prone to breaking due to "cold brittleness." 

Therefore, after starting the diesel engine in winter, let it idle at low to medium speed for a few minutes until the coolant 

temperature reaches 60°C before applying load.

Winter Precaution 7: Pay attention to engine insulation.

Low winter temperatures can cause excessive cooling of the diesel engine during operation. Thus, insulation is key to 

ensuring optimal performance of diesel generator sets in winter. In northern regions, all diesel generator sets used 

in winter should be equipped with cold protection devices such as insulating covers and thermal curtains.