ABYC Diesel Practice Exam

After a reposer, the owner reports overheating at high speed. Which technician is correct?

1. Technician A, who blames the thermostats

2. Technician B, who suggests checking the seawater intake system

3. Both technicians are correct

4. Neither technician is correct

The correct answer is: Technician B, who suggests checking the seawater intake system

Overheating at high speed after a reposer is often related to the cooling system's performance. In this scenario, Technician B’s suggestion to check the seawater intake system is particularly relevant. The seawater intake system is crucial for providing the necessary cooling water to the engine, especially when operating at higher speeds where the engine generates more heat. If the intake system is restricted or clogged, it can lead to inadequate cooling, resulting in overheating issues. This includes checking for blockages in the intake strainer, hoses, or even barnacles or other marine growth inside the seacock that could impede water flow. Technician A’s blame on the thermostats could be a contributing factor in other circumstances, especially if the thermostats were malfunctioning and not allowing the coolant to circulate correctly. However, it is less likely the primary cause in the context of this question, where immediate cooling water supply seems more critical given the reported symptoms. Thus, focusing on the seawater intake system directly addresses the immediate problem of overheating at high speeds, making Technician B's approach the correct one in this situation.