What Should You Do If a Diesel Generator Gets Wet?

With the arrival of spring, rainfall increases, and outdoor diesel generators face the risk of getting wet. If a diesel generator gets wet, it will not only affect its service life and operating efficiency but may also cause damage. Under such weather conditions, diesel generators at outdoor construction sites are particularly susceptible to rainwater intrusion. If a diesel generator is not equipped with a soundproof box, rainwater can easily enter the equipment through various gaps, leading to a series of problems. So, what should we do when a diesel generator gets wet? Today, let's delve into the methods for dealing with a wet diesel generator and how to prevent water ingress to ensure the normal operation of the equipment.

Diesel generators are prone to getting wet in the rainy spring weather. If water enters the generator and is not dealt with in time, it can cause serious damage to the equipment. Therefore, it is crucial to understand the steps to take after a diesel generator gets wet. Here are the detailed steps:

When you discover that a diesel generator has gotten wet, it is important to remain calm. If the generator set is running, shut it down immediately; if it is already off, do not start it. Next, use a solid object to prop up one side of the diesel generator, raising it so that the oil pan's drain area is at the lowest position. Remove the drain plug and pull out the dipstick to allow the water in the oil pan to drain out by itself. When the water is almost drained and the engine oil is about to be released, let a small amount of oil and water drain together before screwing the drain plug back in. This can help minimize the erosion of the engine's interior by water.

Remove the air filter and replace it with a new filter element, which should then be soaked in oil. The air filter's function is to filter the air entering the engine to keep it clean. If the filter element becomes damp, it will affect the quality of the air entering the engine. Then, remove the intake and exhaust pipes as well as the muffler to expel the water inside the pipes. Open the decompression valve and manually rotate the diesel generator to observe whether water is being discharged from the intake and exhaust ports. If water is being expelled, continue to rotate the crankshaft until all the water in the cylinder is completely drained. After that, reinstall the intake and exhaust pipes and the muffler. Add a small amount of engine oil to the intake port and rotate the crankshaft several times before reattaching the air filter. This step ensures that all moisture in the cylinder is thoroughly removed to prevent further damage to the engine from residual water.

Remove the fuel tank and drain all the fuel and water from it. Check the fuel system for the presence of water and drain it completely. Water in the fuel tank can cause the fuel to deteriorate, affecting the engine's performance. Drain the dirty water from the radiator and the water passages, clean the passages, and add clean river water or boiled well water until the water float rises. Clean cooling water can effectively reduce the engine's temperature and prevent it from overheating.

Open the throttle valve and start the diesel engine. After starting the diesel engine, pay attention to the rise of the oil pressure indicator and listen for any abnormal noises from the engine. After checking that all parts are normal, break in the diesel engine. The break-in sequence is to start with idle speed, then medium speed, and finally high speed. After breaking in, shut down the engine and drain the engine oil. Refill with new engine oil, start the diesel engine, and it can then be used normally. The purpose of breaking in is to allow the engine's various components to gradually adapt during the initial operation, reducing wear and extending the engine's service life.

Disassemble the generator and inspect the stator and rotor inside. If moisture is found, it needs to be dried before reassembly. Moisture inside the generator can lead to a decrease in insulation performance, affecting the power generation effect and potentially causing short-circuit faults.

When a diesel generator unfortunately gets wet, it is crucial to take the correct measures in a timely manner. Here are the detailed steps to help you minimize equipment damage and restore normal operation.

For outdoor diesel generators, protective measures are essential. You can equip them with soundproof boxes to prevent rainwater from directly contacting the generator. Additionally, waterproof the exhaust pipe, for example, by creating a bend at the entry point of the diesel generator and installing a drain valve to regularly remove accumulated water. These simple protective measures can effectively reduce the likelihood of rainwater entering the generator.

If you find that the cylinder gasket is damaged, replace it promptly; if there is water leakage at the cylinder liner, replace the cylinder liner seal; if the engine oil cooler of the generator set is leaking, perform a pressure test to identify the leak and repair or replace it; if the water pump is leaking, inspect the water seal and replace the water pump repair kit. Damage to these components can lead to coolant entering the engine, affecting its normal operation.

If the engine block of the generator set is cracked, it needs to be repaired or replaced. A cracked engine block is a serious issue, and if not dealt with in time, it may lead to engine failure. When repairing or replacing the engine block, always choose professional repair personnel or organizations to ensure the quality of the repair or replacement.

Water in the engine oil of a diesel generator set is a relatively hidden but equally serious problem. If not dealt with in time, it can cause irreversible damage to the engine's lubrication system.

Users can heat the engine oil in a test tube. If a slight water sound is heard and water bubbles can be observed, it indicates that there is moisture in the oil. At this point, the different boiling points of oil and water can be utilized for treatment. Continue heating until the water bubbles disappear and the moisture is completely evaporated, then cool the oil to room temperature for continued use.

If the engine oil has emulsified, add 1% to 3% of phenol (carbolic acid) by weight of the oil as a demulsifier. Stir while adding, then preheat the oil for a while, and finally let it stand until the water and oil separate. After completely removing the moisture from the oil, it can be used normally.

Instruments can be used to remove moisture from the diesel generator set. Pour the emulsified oil into a serpentine heating tube and heat it with saturated steam passing through the tube. At the same time, introduce air into the instrument to volatilize the moisture in the oil. Then cool the oil, and it can be used normally.

After understanding the methods for dealing with water in the engine oil of diesel generator sets, we also need to delve deeper into the phenomena and causes of water ingress in the oil pan.

When the oil pan of a diesel generator set gets water ingress, the following phenomena may occur: abnormal reduction in cooling water; decrease in engine oil pressure. If the engine oil pressure decreases by 100 to 200 kPa at the same speed, it is necessary to check the cause promptly; after continuous operation or being left idle for several hours, the oil level in the oil pan rises significantly, meaning the engine oil increases instead of decreasing, sometimes overflowing from the dipstick; at the initial stage of water ingress into the oil pan, there are water droplets in the engine oil, and over time, the engine oil turns milky white; the cooling water shows "boiling" or "bubbling" phenomena.

The main causes of water ingress in the oil pan of generator sets are as follows:

Improper repair and use: Long-term high-load operation, excessive thermal load and thermal stress; adding a large amount of cold water to the diesel generator set when it is at high temperature and lacks water; or damage caused during disassembly, assembly, and transportation; or accidental damage resulting in wear and cracks.

Cylinder liner issues: The cylinder liner is in direct contact with the cooling water of the diesel generator set for heat dissipation. During the circulation of the cooling water, it will erode the outer surface of the cylinder liner, causing water and cavitation phenomena. Over time, dense pits may appear on the outer surface of the cylinder liner facing the water, and in severe cases, the cylinder liner may be perforated, allowing cooling water to enter the oil pan of the diesel generator set. When installing the cylinder liner, if the centerline of the cylinder liner is not perpendicular to the end face of the cylinder block support hole, or if excessive force is applied during installation, the water seal ring may be damaged; or if the generator set operates in a water-deficient state, the high temperature of the cylinder liner may damage the water seal ring, causing cooling water to leak into the oil pan.

Radiator issues: The radiator core is composed of a row of copper tubes, through which the oil flows. The lubricating oil of the diesel generator set circulates outside the radiator core. During the flow, the high-temperature engine oil is cooled by the coolant to maintain a certain oil temperature. When the seals at both ends of the radiator core fail, the coolant may enter the diesel lubricating oil pan through the lubricating oil passage. Or, if the water level in the water tank is higher than the oil radiator, the pressure difference caused by the height difference may cause the cooling water to pass through the radiator tubes and enter the diesel lubricating oil pan through the lubricating oil passage. Additionally, if the seals between the ends of the radiator core and the radiator housing fail, cooling water may enter the oil pan.

Cylinder gasket issues: If the generator set operates abnormally and overheats, it will cause the cylinder gasket to be burned and damaged, leading to water leakage; if the cylinder gasket is not installed flat or the installation direction is incorrect, it will also cause the gasket to be damaged and leak water; and if there are impurities between the cylinder gasket and the cylinder head or cylinder block during assembly, the cylinder gasket will not seal properly and leak water. These conditions can disrupt the cylinder's operation and lubrication, causing water to flow into the oil pan and leading to engine oil emulsification, which affects the lubrication performance of the generator set.

Water pump issues: Normally, when the water seal of the water pump fails, water will flow out from the overflow hole. If the overflow hole is blocked by dirt, water will flow along the water pump shaft into the front gear box of the generator set and then enter the oil pan. Therefore, it is necessary to regularly clean the overflow hole of the water pump during operation, and replace the water seal promptly if water leakage is detected.

In the rainy spring, outdoor diesel generators face the risk of getting wet. When a diesel generator gets wet, we can deal with it through emergency shutdown, drainage, replacement and cleaning of components, inspection and cleaning of the fuel tank, break-in and inspection, as well as internal inspection and drying of the generator. At the same time, to prevent water ingress in diesel generators, we also need to take protective measures, replace damaged components in a timely manner, and repair or replace ruptured components. For the issue of water in the engine oil of diesel generator sets, we can deal with it through heating treatment, demulsification treatment, and instrumental dehydration. Understanding the phenomena and causes of water ingress in the oil pan of diesel generator sets, as well as the possible causes and treatment methods for water entering the oil pan, can help us better manage and maintain diesel generators to ensure their normal operation in the rainy spring weather. I hope the above content is helpful to everyone. Let's work together to take good care of diesel generators and ensure the stable operation of the equipment.