THE REASONS FOR THE HIGH WATER TEMPERATURE DURING DIESEL ENGINE OPERATION ARE AS FOLLOWS:1. THE WATER TANK FAN DOES NOT TURNTHE SIMPLEST WAY TO CHECK IF THE WATER TANK FAN IS RUNNING PROPERLY IS TO TURN ON THE REFRIGERATION SYSTEM. IF THE COMPRESSOR HAS ALREADY STARTED BUT THE FAN IS STILL NOT RUNNING, THEN THE FAN MUST HAVE MALFUNCTIONED; WHEN THE WATER TEMPERATURE SENSOR IS DISCONNECTED, THE FAN WILL OPERATE ON ITS OWN TO PROTECT THE ENGINE. IN SUCH A SITUATION, THE WATER TEMPERATURE SENSOR CAN BE UNPLUGGED FOR JUDGMENT.2. POOR HEAT DISSIPATION OF THE RADIATORTHIS SITUATION OFTEN OCCURS IN SUMMER. WHEN CHECKING, SIMPLY OPEN THE ENGINE HOOD TO OBSERVE WHETHER THERE ARE TOO MANY FOREIGN OBJECTS IN THE RADIATOR LOCATED BEHIND THE BUMPER. IF THE RADIATOR IS TOO CLOGGED, IT NEEDS TO BE CLEANED AT A REPAIR SHOP.3. THE THERMOSTAT CANNOT BE OPENED NORMALLYIN THIS CASE, THE COOLANT CANNOT CIRCULATE NORMALLY AND CANNOT PLAY A COOLING ROLE AT ALL. THE MAIN MANIFESTATION IS THAT THE WATER TANK AND RETURN PIPE ARE AT ROOM TEMPERATURE (WHICH SHOULD BE HOT UNDER NORMAL CIRCUMSTANCES), AND DUE TO THE EXPANSION OF GAS INSIDE THE WATER PIPE, BOTH THE UPPER AND LOWER PIPES WILL BECOME VERY HARD.4. INSUFFICIENT COOLANTTHIS IS A RELATIVELY EASY SITUATION TO OBSERVE, AS LONG AS THE ENGINE COMPARTMENT IS OPENED TO OBSERVE WHETHER THE COOLANT LEVEL MEETS THE REQUIREMENTS.5. POOR OPERATION OF WATER PUMPTHE WATER PUMP BELT MAY SOMETIMES SLIP OR SPIN DUE TO PROLONGED USE. WHEN THIS PROBLEM OCCURS, THE MAIN CHARACTERISTIC IS THAT IT WILL RETURN TO NORMAL AFTER PRESSING AND HOLDING THE ACCELERATOR FOR A PERIOD OF TIME.6. ABNORMAL WATER TEMPERATURE SENSOR, INSTRUMENT AND CIRCUITIF ALL THE ABOVE PROBLEMS HAVE BEEN ELIMINATED, THEN THE HIGH WATER TEMPERATURE MAY BE CAUSED BY A MALFUNCTION OF THE WATER TEMPERATURE SENSOR OR A MALFUNCTION OF THE INSTRUMENT OR CIRCUIT. IN THIS CASE, IT IS NECESSARY TO PROMPTLY GO TO A MAINTENANCE SERVICE POINT FOR A DETAILED INSPECTION.