MDE 4 End of Unit Quiz

MDE 4 End Of Unit Quiz

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Components of a Resilient/Flexible Engine Mounting

Question: In a cross section through a resilient/flexible mounting for a diesel engine, what are the MAIN components typically found? (Select THREE)

F) Fastening bolts

A) Mounting brackets

D) Rubber or elastomeric pads

B) Vibration isolators

E) Shock absorbers

C) Engine support beams

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5. Effect of Pulse System on Exhaust Temperature

Question: How does a pulse system typically affect the exhaust temperature in a turbocharged diesel engine?

C) It may increase exhaust temperature by optimizing the utilization of exhaust gases

B) It has no impact on the exhaust temperature

D) It drastically reduces exhaust temperature to prevent turbocharger overheating

A) It significantly lowers the exhaust temperature by reducing exhaust gas pressure

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4. Possible Cause: Intake System Blockage

Question: What is a potential cause of reduced boost pressure if there is a blockage in the intake system?

C) A broken exhaust manifold

B) A leaking radiator hose

A) A blocked or restricted intake pipe or manifold

D) A malfunctioning alternator

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Pulse System in Turbochargers

Question: What is meant by the term "pulse system" in the context of large medium-speed diesel engine turbochargers?

A) A system that uses multiple turbochargers operating in sequence to boost overall engine power

B) A system that utilizes a series of exhaust gas pulses to improve the efficiency of the turbocharger by enhancing turbine response and performance

D) A system designed to reduce the noise generated by the turbocharger during operation

C) A system that measures and adjusts the pulse frequency of the engine's fuel injection to optimize combustion

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2. Malfunctioning Turbocharger or Worn Turbine Blades

Question: What is a basic maintenance routine that could help with a malfunctioning turbocharger or worn turbine blades?

D) Change the engine's spark plugs

B) Replace the turbocharger with a new unit

C) Adjust the engine's fuel mixture

A) Check and clean the turbocharger air intake and exhaust areas

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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

C) An incorrect engine timing setting

B) A faulty ignition system

D) A malfunctioning air conditioning system

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Purpose of Tube Fins in Air Coolers

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

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

B) To support the structural integrity of the cooler tubes

C) To reduce the weight of the air cooler

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Turbocharger Lubrication

Question: How is a turbocharger typically lubricated in a marine diesel engine?

C) By using a separate lubrication system dedicated to the turbocharger

B) By circulating engine lubricating oil through the turbocharger bearings under pressure

D) By mixing lubricating oil with the fuel before combustion

A) By injecting grease directly into the turbocharger bearings

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Indications of Poor Turbocharger Performance

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

A) Increased turbo lag and delayed acceleration

F) Reduced power output and overall engine performance

E) Decreased engine coolant temperature

D) Unusual whining or rattling noises from the turbocharger

B) Excessive exhaust smoke or black smoke from the engine

C) Higher engine oil temperature than usual

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Purpose of the Thrust Bearing in Turbochargers

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

A) To support the radial load of the rotating components and reduce friction

B) To absorb and manage the axial forces generated by the high-speed rotation of the turbocharger shaft

D) To increase the intake air pressure before it reaches the engine cylinders

C) To cool the turbocharger by directing airflow through the bearing housing

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4. Consequence of a Faulty Air Cooler

Question: What is a likely consequence if an air cooler fails or becomes inefficient on a turbocharged diesel engine?

A) Increased engine cooling efficiency

B) Lower exhaust gas temperature and reduced power output

D) Improved fuel economy and lower engine emissions

C) Higher intake air temperature, leading to reduced engine efficiency and increased risk of knocking

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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?

A) Accumulation of dirt and debris on the cooler fins

C) A malfunctioning spark plug

D) A blocked fuel filter

B) Excessive engine oil consumption

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