Question 49 MODE02 - Assistant MODU Engineer

The Correct Answer is A. **Explanation for Option A (Correct):** A safety shutdown triggered by high lubricating oil temperature indicates a critical failure condition (e.g., cooling system failure, pump failure, excessive friction). When a hot engine trips, immediate inspection is dangerous and ineffective. The components (oil, bearings, metal) are extremely hot and stressed. Allowing a significant period (such as 2 hours, or until components are cool enough to safely touch/work on) ensures that thermal expansion has normalized, high internal pressures have dissipated, and oil has drained back, making it safe to open inspection covers and effectively diagnose the mechanical or thermal fault. Furthermore, attempting to diagnose a hot engine immediately risks severe burns and can lead to misleading inspection results. The engine must be cool before inspection and repair are attempted, and the cause of the trip must be corrected *before* any restart attempt. **Explanation for Incorrect Options:** **B) Immediately perform the engine inspections to determine the cause of the high oil temperature safety shutdown.** This is incorrect primarily due to safety and accuracy concerns. An engine that has just shut down due to excessive heat is dangerously hot. Attempting immediate inspection (e.g., checking bearing clearances, opening oil filters, or removing hot piping) poses a significant risk of severe burns to personnel. Moreover, the heat causes components to expand, which can make accurate diagnosis (like checking clearances) impossible or misleading. **C) Immediately restart the engine and monitor the oil temperature to verify the cause of the shutdown.** This is severely incorrect and dangerous. A safety shutdown means a limit has been exceeded, likely preventing catastrophic damage (like bearing wipe). Attempting an immediate restart without finding and fixing the root cause guarantees the high temperature condition will return, potentially leading to immediate and catastrophic engine failure (seizure, fire, or total bearing destruction). **D) Allow the engine to cool off for two minutes, then restart and monitor the lubricating oil temperature to verify the cause of the shutdown.** Two minutes is wholly insufficient time for a large diesel engine to cool down from an overheated state. This option carries the same critical fault as Option C—attempting to restart an engine without diagnosing and correcting the underlying safety fault is reckless and will likely result in permanent engine damage.