Question 90Motor Plants - QMED

The correct answer is A) The oil pressure is greater than the cooling water pressure. This is the correct answer because in a main diesel engine oil cooler, the oil needs to be at a higher pressure than the cooling water in order to flow through the cooler. This allows the oil to be effectively cooled by the lower-pressure cooling water. The higher oil pressure ensures that the oil can circulate through the cooler and return to the engine. The other options are incorrect - B) is not always the case, C) would indicate an issue with the cooler, and D) would be the opposite of the required pressure relationship.