Exam 14: Air Induction and Crankcase Ventilation Systems

Technician A says that crankcase coalescing filters are used to minimize particulate emissions from diesel engines. Technician B says that centrifugal separators of air and oil reduce engine oil consumption. Who is correct?

What are multistage filtration devices used for crankcase ventilation designed to do?

The service interval of an air filter is best determined by which of the following?

Technician A says that it is acceptable practice to clean air filters by using compressed shop air. Technician B says it is better to clean air filters by dropping or lightly tapping the filter against the shop floor. Who is correct?

Technician A says that nitrous oxide (N2O) contains five times as much oxygen as a cubic foot of air. Technician B says that adding nitrous oxide (N₂O) can supplement the oxygen in the intake air charge to supply a power boost. Who is right?

Two technicians are describing coalescing filtration. Technician A says that crankcase vapors are regulated, so an emission monitor system often uses a crankcase pressure sensor to detect whether the filter is plugged or missing. Technician B says that coalescing filters, which return oil back to the sump tend to increase oil consumption. Who is right?

Which of the following refers to the minimum quantity of air required to completely consume fuel in the combustion chamber with no air or fuel remaining after combustion?

A pre-cleaner will typically remove _____ of all airborne contaminants.

Which of the following located at the elbows of inlet air tubes and in air filter housings assist in removing water and dirt that enter the induction system?

Technician A says that diesel engines use more air than gasoline-fueled engines because 1 gallon (3.7 liters) of diesel fuel requires more air to burn than the same amount of gasoline. Technician B says that a diesel engine uses more air to prevent pistons and valves from burning. Who is correct?

Since the flame temperature of diesel is near 3,990°F (2,167°C) it will easily melt pistons and burn valves, which of these is important to cool piston crowns and exhaust valves?

Which of the following tends to create a high degree of intake air swirl?

What is the dust-holding capacity of a filter with a pressure drop of 9.9 inches of H₂O?

A diesel engine of 350 bhp typically requires an air intake capacity of close to ____ cubic feet per minute (cfm).

While two technicians are examining a piston crown that has vertical cracks through the edges of the piston's combustion chamber bowl, Technician A suggests the piston crown was not getting properly cooled due to low mass airflow in the combustion chamber during the valve overlap period. Technician B suggests the cracks were caused by inadequate cooling by the oil cooler nozzles. Who is correct?

Technician A says that diesel engines use more air than gasoline-fueled engines because 1 gallon (3.7 liters) of diesel fuel requires more air to burn than the same amount of gasoline. Technician B says that a diesel engine uses more air to prevent pistons and valves from burning. Who is correct?

Which air inlet sensor is used to provide data regarding atmospheric air pressure for altitude compensation?

In a diesel engine, blowby leaking past the rings consists primarily of:

Which of the following air intake systems will best pre-clean dirt and water from the air intake of an on-highway, diesel-powered vehicle?

Technician A says that the best practice is to replace air filters on turbocharged engines when the restriction gauge reads 20-25" (51-63 cm) of H₂O. Technician B says the filter should be replaced around 10-15" (25-38 cm) H₂O to prevent increased fuel consumption caused by a restricted air filter. Who is correct?