229. If an auxiliary diesel engine is overheating at a steady load, what should be the first thing that you suspect?

Loss of cooling water flow is the most likely cause of an auxiliary diesel overheating at a steady load. At a steady load, heat generation is constant, so a failure in heat rejection, specifically a loss of cooling water flow, is the primary suspect. Other issues like excessive fuel, blocked air intake, or low lube oil pressure typically present with different symptoms or are less likely to cause a sudden overheat at a constant load.