Question

Which are the parts that get damaged when dirt enters the crankcase?

(a) Heavy-duty type air cleaner

(b) Light duty type air cleaner

(c) Thermostatic control of air cleaner

(d) Heavy-duty type air cleaner and Light duty type air cleaner

This question was posed to me during a job interview.

This intriguing question comes from Petrol Engine Fuel Supply System in section Petrol Engine Fuel Supply System of Automotive Engine Design

Answer 1

Correct choice is (d) Heavy-duty type air cleaner and Light duty type air cleaner

The best I can explain: If the dirty air enters the crankcase, it will contaminate the lubricating oil and ultimately damage the bearings and journals and decrease the service period of the lubrication system.