8971256011 Original Excavator Parts Water Temperature Sensor for ISUZU 4HK1 Engine

The Hitachi original ISUZU 4HK1 engine water temperature sensor (part number: 8971256011) is a key electronic component used to monitor the temperature of the engine coolant. According to existing information, this part number is mainly associated with Isuzu 6BG1 and 6BD1 series engines. It may also be compatible with some Hitachi excavator models equipped with Isuzu 4HK1 engine, such as Hitachi ZX200-3, ZX240-3, etc. Its common part number may include 8-97125601-1, etc.

The water temperature sensor is the "temperature sentinel" of the engine management system, whose core function is to monitor the engine coolant temperature in real time and convert the temperature signal into a resistance value or voltage signal, which is transmitted to the engine control unit (ECU) or dashboard water temperature gauge. ECU precisely controls fuel injection quantity, ignition timing (gasoline engine), fan start stop, and cold start enrichment based on this signal to optimize combustion efficiency, reduce emissions, and prevent engine overheating or overcooling operation. As an original component, it is made of materials that are resistant to high temperature, corrosion, and vibration (such as stainless steel shell and NTC thermistor core), and has the characteristics of fast response speed, high measurement accuracy, and stable and reliable operation. Its electrical interface is usually a single or double pin plug, with thread specifications strictly matching the installation holes on the engine block or water pipe, and equipped with sealing rings to prevent coolant leakage.

The maintenance core of this water temperature sensor lies in regularly checking its signal accuracy, electrical connection reliability, and self sealing. Daily inspection: It is recommended to observe whether the water temperature indicator on the dashboard is abnormal (such as always displaying low or high temperature) every 500 working hours or every month, and check whether the sensor plug and wiring harness are loose, corroded, or damaged. Replacement operation: Before replacement, be sure to wait for the engine to completely cool down and release the cooling system pressure. Use a sleeve of appropriate size during disassembly to avoid damaging the sensor housing or threads. Before installing a new sensor, clean the installation threaded hole and apply a small amount of anti sticking agent (such as high-temperature sealant or engine oil) on the sealing ring or thread of the new sensor, then tighten it with the specified torque (usually 15-25N · m).