With the arrival of summer, many truck drivers’ engines overheat when climbing hills with heavy loads. Seeing the water temperature gauge soar, some drivers are at a loss. How can this situation be addressed and repaired?
There are two approaches: mechanical maintenance and improving driving habits.
● Mechanical Maintenance
1. Cleaning Willow Catkins and Dead Insects from the Radiator
In spring, willow catkins are abundant in northern China, easily clogging the radiator surface with these dead insects. Trucks frequently operating in northern regions require a thorough annual cleaning of the radiator. Since current truck radiators often feature a multi-layer design consisting of an air conditioning condenser, intercooler, and radiator, it’s recommended to remove the radiator for cleaning to ensure optimal performance.
2. Checking the Fan Clutch for Proper Operation
Most trucks are equipped with a silicone oil fan clutch, which adjusts the fan speed in real time based on engine temperature, reducing power consumption and increasing engine temperature control accuracy. A faulty silicone oil fan clutch can cause the fan to operate at low speed when full speed is required, failing to meet cooling requirements. The diagnosis is relatively simple. Most silicone oil fan clutches are equipped with a temporary locking device. Once locked, the fan becomes rigidly connected. If the high-temperature fault disappears, the fault is in the silicone oil fan clutch. If it does not, the fault is elsewhere and requires further investigation. It’s important to note that the silicone oil fan clutch should only be temporarily locked for testing and should not be used for extended periods. Otherwise, at best, power loss and fuel consumption may be significant, while at worst, the fan connection shaft may be damaged due to the immense inertia, causing the truck to break down mid-route.
3. Check the Engine Injectors
In electronically controlled high-pressure common rail engines, worn and damaged injectors may cause the injection rate to exceed the rated value. While this will improve power performance, the maximum engine load will exceed the factory limit, generating heat that exceeds the cooling capacity of the engine cooling system, causing engine overheating. However, this fault is relatively uncommon.
● Improve Driving Habits
In addition to vehicle-related issues, improper driving under extreme conditions can also cause engine overheating. A key performance indicator for trucks is thermal balance, which means that under certain operating conditions, the heat generated by the engine and the vehicle’s heat dissipation capacity can reach a balance, preventing further temperature increases.
However, in real-world use, we sometimes overload, sometimes encounter slopes exceeding 7%, and continuous climbing times are unlikely to be just four minutes. The speed is also likely to be less than 25 kilometers per hour. The lower the speed, the lower the headwind, which is less conducive to heat dissipation.
So, it’s not surprising that trucks can run hot under these extreme conditions. You can downshift, reduce the load, and increase the engine speed. By changing your driving habits, you can effectively avoid overheating caused by overloading the cooling system.
● No need to clean the interior; use water sprays with caution.
Some repair shops recommend cleaning the inside of the radiator, but this is actually unnecessary. Most modern trucks use a dedicated coolant that won’t cause scale buildup inside the radiator. Cleaning the inside of the radiator is a legacy from the days when trucks used water for cooling and is no longer suitable for today’s vehicle environments.
Some truck drivers also use a water sprayer to spray the radiator. This method only treats the symptoms, not the root cause. Overtime, a layer of scale forms on the radiator’s outer surface, impairing heat dissipation.
● Postscript
Overheating is one of the most common summer truck malfunctions. If left untreated, it can easily lead to serious problems like cylinder seizure and sticking. In addition to the aforementioned causes, components like the thermostat and exhaust brake butterfly valve can also contribute to engine overheating. Only by identifying the cause and addressing it, can the cooling system function properly and continue to enjoy a cool summer!
