Question 250Motor Plants - Assistant Engineer

The correct answer is D) Crankcase explosion. The accumulation of oil vapors in the crankcase of a diesel engine can lead to a potentially dangerous crankcase explosion. This is due to the flammable nature of the oil vapors, which can ignite and cause a sudden pressure increase within the crankcase. This sudden pressure increase can then lead to the crankcase rupturing or exploding. The other options are incorrect because: A) Reduced lubrication is not a direct consequence of oil vapor accumulation. B) Poor fuel economy is not directly related to the crankcase oil vapor issue. C) Combustion knock is typically caused by issues with fuel ignition, not crankcase oil vapors.