Engine overheating is one of the most common and troublesome faults in diesel engines for construction machinery and heavy equipment. Frequent high engine temperature will not only reduce equipment operating efficiency and increase fuel consumption, but also easily cause cylinder pulling, part aging and other serious failures, greatly shortening the service life of the engine. To help you quickly troubleshoot and solve the overheating problem, we have sorted out the six core reasons for frequent engine overheating in daily operation, with targeted analysis for your reference.
1. Long-term Overload Operation
When the engine works under overload conditions for a long time, the internal combustion load will increase sharply. In this case, the engine needs to consume more fuel to provide sufficient power, resulting in a continuous rise in internal heat load. The heat generated by operation far exceeds the heat dissipation capacity of the original cooling system, which eventually leads to a continuous rise in water temperature and triggers engine overheating.
2. Insufficient Coolant Volume
Coolant is the core medium for engine heat dissipation. If the coolant in the cooling system is insufficient due to leakage, volatilization or untimely refilling, the normal circulating heat dissipation of the engine cannot be guaranteed. The lack of coolant will directly weaken the heat exchange efficiency of the cooling system, making the engine heat unable to be discharged in time, and causing persistent high temperature failure of the diesel engine.
3. Mutual Heat Interference of Heat Dissipation Devices
For engineering mechanical equipment, most of the hydraulic oil radiator and water radiator are installed in front and rear alignment. When the hydraulic system works continuously, the temperature of hydraulic oil will rise rapidly. The high-temperature hydraulic oil radiator will heat the passing cold air in advance, resulting in the increase of inlet air temperature of the water radiator. The cold air required for engine heat dissipation loses its low-temperature heat exchange advantage, which seriously affects the heat dissipation efficiency of the water radiator and causes engine overheating.
4. Abnormal Fan Belt & Fan Deformation
The cooling fan relies on the belt to transmit power and maintain a stable operating speed. If the fan belt is too loose, slipping will occur during operation, which directly reduces the fan speed. Insufficient fan air volume makes the radiator unable to give full play to its heat dissipation performance.
In addition, long-term vibration and external impact during equipment operation may cause fan deformation. The deformed fan cannot form uniform and stable air flow, resulting in poor heat dissipation circulation and eventually engine high temperature failure.
5. Dust and Debris Accumulated on Radiator Surface
Construction machinery mostly works in harsh environments such as dust, gravel and mud. Long-term operation will make a large amount of dust, debris and mud adhere to the surface of the radiator. These sundries will cover the heat dissipation fins, reduce the actual heat dissipation area and windward air intake area of the radiator.
Blocked heat dissipation channels will greatly reduce the heat exchange capacity of the radiator, so that the engine heat cannot be discharged outward normally, which is a common hidden danger of frequent overheating of equipment in daily use.
6. Poor Coolant Circulation Efficiency
Unsmooth coolant circulation is an internal core cause of engine overheating, which is mainly affected by two key components: thermostat and water pump.
A stuck or insufficiently opened thermostat will limit the large circulation state of the engine cooling system, reduce the overall heat dissipation efficiency of the system, and make it impossible to quickly dissipate high temperature.
The performance degradation of the water pump is also a key factor. The aging and failure of the water pump will lead to reduced coolant circulation flow and insufficient power to drive the coolant circulation. It is worth noting that you can judge the water pump status by detecting the temperature difference between the upper and lower water chambers of the radiator. The normal temperature difference is 6-12℃; if the temperature difference is too small, it means the water pump is faulty and needs to be replaced in time.
Moreover, long-term use will produce a lot of scale inside the radiator. Scale will cover the internal heat dissipation fins, hinder the heat conduction between coolant and cold air, reduce the heat dissipation efficiency of the cooling system, and cause continuous high temperature of the engine.
Summary
Engine overheating is not a single fault, but is mostly caused by improper operation, aging parts, environmental blockage and system failure. Daily regular inspection of coolant volume, radiator cleanliness, fan operating status and cooling system circulation can effectively avoid frequent overheating failures, reduce equipment maintenance costs and extend the service life of the engine.
