An engine has a crack between a water jacket and an oil gallery. Technician A says that oil will go into the cooling system when the engine is running. Technician B says that coolant will go into the oil when the engine is off. Who is right?
A)Technician A only
B)Technician B only
C)Both A and B
D)Neither A nor B

Question

Quizplus · Accepted Answer

Both technicians are correct. When the engine is running, the oil pressure is typically higher than the coolant pressure, which can cause oil to enter the cooling system. When the engine is off and cools down, the pressure in the cooling system can become higher than in the oil system, allowing coolant to seep into the oil.

An Engine Has a Crack Between a Water Jacket and an Oil