Case Study: Thermostat Failure Causing Undercooling Detected by DataMind AI in Komatsu 930E

Undercooling in large haul trucks is often overlooked because it does not trigger high-temperature alarms, yet prolonged operation below optimal temperature causes increased engine wear and reduced service life. DataMind AI continuously monitors coolant temperature trends, coolant pressure, oil pressure, and ambient conditions, enabling early detection of thermal regulation faults that conventional monitoring misses.

In this case, DataMind AI identified a sustained downward coolant temperature trend on a Komatsu 930E since December 7, with values ranging between 60 and 70°C, significantly below the normal operating range of 85-95°C. Coolant pressure at 416 kPa and oil pressure at 460 kPa both remained within normal limits, ruling out fluid leaks or mechanical failure. Ambient temperature readings appeared normal, eliminating environmental cold-soak as a cause.

By correlating the sustained low coolant temperature with normal pressures and ambient conditions, DataMind AI identified the root cause as a thermostat stuck in the open position, allowing continuous coolant flow to the radiator and preventing the engine from reaching operating temperature. An improvement in coolant temperature trending from January 15 confirmed the diagnosis following thermostat service.

Based on the early detection, the maintenance team verified thermostat operation and replaced the faulty unit, restoring normal temperature. The operation avoided approximately $12,000 in accelerated wear costs and prevented 8 hours of unplanned downtime.