MDE 4 End of Unit Quiz

MDE 4 End Of Unit Quiz

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1. Air Leak in Intake System or Charge Air Cooler

Question: What is a simple and economical maintenance routine to address an air leak in the intake system or charge air cooler?

D) Replace the engine oil and filter

A) Tighten all intake and charge air cooler clamps and inspect for visible damage

C) Clean the engine air filter

B) Replace the turbocharger with a new unit

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1. Purpose of Air Coolers After Turbochargers

Question: Why are air coolers (intercoolers) typically fitted after the main engine turbochargers?

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

C) To reduce the engine's overall weight and improve its fuel efficiency

B) To decrease the temperature of the intake air, increasing its density and improving engine efficiency

D) To eliminate moisture from the intake air and prevent engine corrosion

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Purpose of the Nozzle Ring in Turbochargers

Question: What is the primary purpose of the nozzle ring in a main engine turbocharger?

B) To direct and accelerate exhaust gases onto the turbine wheel for improved energy extraction

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

C) To cool the exhaust gases before they enter the turbine

A) To regulate the flow of lubricating oil to the turbocharger bearings

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Purpose of Zinc Anodes in Air Coolers

Question: What is the purpose of zinc anodes in air coolers?

A) To enhance the cooling efficiency of the air cooler

D) To reduce the noise generated by the air cooler

C) To increase the pressure of the air passing through the cooler

B) To prevent corrosion by providing a sacrificial material that corrodes instead of the cooler components

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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?

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

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

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

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

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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

D) It drastically reduces exhaust temperature to prevent turbocharger overheating

B) It has no impact on the exhaust temperature

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

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Purpose of Tube Fins in Air Coolers

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

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

C) To reduce the weight of the air cooler

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

B) To support the structural integrity of the cooler tubes

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1. Advantages of Pulse Systems

Question: What is one of the main advantages of using a pulse system in a turbocharged diesel engine?

C) It eliminates the need for a separate intercooler

B) It enhances the efficiency of the turbocharger by improving turbine response and reducing turbo lag

D) It simplifies the engine's fuel injection system

A) It reduces the overall weight of the turbocharger

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Indications of Poor Turbocharger Performance

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

F) Reduced power output and overall engine performance

A) Increased turbo lag and delayed acceleration

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

E) Decreased engine coolant temperature

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1. Possible Cause: Air Leak

Question: What is one possible cause of reduced boost pressure at the inlet manifold in a turbocharged engine fitted with a charge air cooler?

C) A faulty fuel injector

B) An air leak in the intake system or charge air cooler

A) A clogged air filter

D) Excessive engine oil consumption

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3. Troubleshooting Pulse System Issues

Question: What could be a symptom of a problem with the pulse system in a turbocharged diesel engine?

A) Increased engine noise and vibration

D) Increased coolant temperature

B) Reduced engine responsiveness and increased turbo lag

C) Decreased engine oil temperature

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4. Maintenance of Pulse Systems

Question: What is an important maintenance consideration for ensuring the proper function of a pulse system in a turbocharged engine?

D) Adjusting the engine’s timing to match pulse frequencies

A) Regularly replacing the turbocharger bearings

B) Ensuring proper alignment and integrity of the pulse piping and valves

C) Increasing the fuel injection pressure to compensate for pulse system inefficiencies

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