Question 472Motor Plants - Assistant Engineer

The correct answer is C) lube oil cooler failure. A lube oil cooler failure can allow lube oil to enter the fresh water cooling system of a diesel engine. This happens because the lube oil cooler is designed to keep the lube oil separate from the fresh water cooling system. If the cooler develops a leak or fails, it can allow lube oil to mix with the fresh water, resulting in lube oil contamination in the cooling system. The other answer choices are incorrect because they would not directly allow lube oil to enter the fresh water cooling system. A camshaft seizure, lube oil pump failure, or lube oil sump overflow would not necessarily result in lube oil entering the cooling system.