MDE 4 End of Unit Quiz

MDE 4 End Of Unit Quiz

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Purpose of the Inducer in Turbochargers

Question: What is the primary purpose of the inducer in the construction of a diesel engine turbocharger?

B) To draw in and compress the intake air before it enters the compressor wheel

A) To direct the exhaust gases onto the turbine wheel for efficient energy extraction

D) To enhance the flow of lubricating oil to the turbocharger bearings

C) To increase the temperature of the intake air for better combustion

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Purpose of Fins on Charge Air Cooler Tubes

Question: Why are fins attached to the tubes of a charge air cooler?

A) To increase the surface area for heat dissipation and enhance the cooling efficiency of the air

D) To provide a mounting point for additional components

C) To reduce the weight of the charge air cooler

B) To strengthen the structural integrity of the cooler tubes

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Possible Causes of Poor Turbocharger Performance

Question: What are possible causes of poor turbocharger performance? (Select FOUR)

C) An air leak in the intake system

B) A malfunctioning fuel injector

F) Low engine oil level

D) A worn-out or damaged turbocharger turbine

E) A restricted exhaust system

A) A clogged air filter

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5. Maintenance of Air Coolers

Question: What is an important maintenance task for ensuring the efficient operation of air coolers in a turbocharged diesel engine?

D) Adding fuel additives to the diesel fuel

C) Reducing the engine's operating temperature

A) Regularly replacing the turbocharger

B) Cleaning the air cooler to remove any buildup of dirt or oil

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Cooling the Air Outlet from the Turbocharger

Question: Why should the air outlet from the turbocharger be cooled before entering the diesel engine cylinder?

A) To reduce the pressure of the air to avoid engine damage

C) To increase the temperature of the air for better fuel atomization

B) To lower the temperature of the air, increasing its density and improving combustion efficiency

D) To remove excess moisture from the air to prevent corrosion

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2. Possible Cause: Turbocharger Failure

Question: What could be a reason for a reduction in boost pressure over time in a turbocharged engine?

A) A malfunctioning turbocharger or worn turbine blades

B) A faulty ignition system

C) An incorrect engine timing setting

D) A malfunctioning air conditioning system

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Thrust Bearing in Turbochargers

Question: Why is a thrust bearing necessary in a large medium-speed diesel engine turbocharger?

A) To support the weight of the turbocharger and reduce vibrations

B) To absorb axial forces generated by the high-speed rotation of the turbocharger's compressor and turbine wheels

D) To maintain proper alignment of the turbocharger housing with the engine block

C) To enhance the cooling of the turbocharger by directing airflow

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Purpose of Tube Fins in Air Coolers

Question: What is the purpose of tube fins in air coolers?

B) To support the structural integrity of the cooler tubes

C) To reduce the weight of the air cooler

D) To filter out debris from the air passing through the cooler

A) To increase the surface area for heat exchange, enhancing the cooling efficiency

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Purpose of the Diffuser in Turbochargers

Question: What is the primary purpose of the diffuser in the construction of a diesel engine turbocharger?

B) To reduce the pressure of the exhaust gases before they reach the turbine wheel

C) To slow down the high-velocity air exiting the compressor and convert kinetic energy into increased pressure

D) To filter out impurities from the intake air before it reaches the compressor

A) To increase the temperature of the compressed air before it enters the intake manifold

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Purpose of Labyrinth Glands in Turbochargers

Question: What is the primary purpose of labyrinth glands in the construction of a diesel engine turbocharger?

C) To cool the turbocharger by circulating coolant around the bearings

B) To prevent the leakage of lubricating oil and seal the gap between the rotating shaft and stationary components

D) To increase the intake air pressure before it reaches the compressor wheel

A) To provide additional lubrication to the turbocharger bearings

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Possible Reasons for Reduced Charge Air Cooler Performance

Question: What are possible reasons why the performance of a charge air cooler may be reduced?

D) A blocked fuel filter

A) Accumulation of dirt and debris on the cooler fins

C) A malfunctioning spark plug

B) Excessive engine oil consumption

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Lubrication of Thrust Bearing in Turbochargers

Question: How is the thrust bearing typically lubricated in a large medium-speed diesel engine turbocharger?

A) By grease that is manually applied during maintenance intervals

C) By a dedicated oil pump that supplies pressurized lubricating oil directly to the bearing

D) By the engine’s lubricating oil system, which circulates oil through the turbocharger bearing housing

B) By engine coolant circulating through the bearing housing

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