MDE 4 End of Unit Quiz

MDE 4 End Of Unit Quiz

1 / 12

3. Damaged or Clogged Charge Air Cooler

Question: What is an economical maintenance routine to address a damaged or clogged charge air cooler?

C) Adjust the engine timing

A) Inspect and clean the charge air cooler, and replace it if necessary

B) Replace the entire intake manifold

D) Flush the engine cooling system

2 / 12

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?

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

D) Excessive engine oil consumption

A) A clogged air filter

C) A faulty fuel injector

3 / 12

Indications of Poor Turbocharger Performance

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

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

A) Increased turbo lag and delayed acceleration

C) Higher engine oil temperature than usual

4 / 12

Turbocharger Lubrication

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

A) By injecting grease directly into the turbocharger bearings

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

D) By mixing lubricating oil with the fuel before combustion

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

5 / 12

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?

A) Regularly replacing the turbocharger

D) Adding fuel additives to the diesel fuel

C) Reducing the engine's operating temperature

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

6 / 12

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

D) A malfunctioning air conditioning system

C) An incorrect engine timing setting

B) A faulty ignition system

7 / 12

Location of Thrust Bearing in Turbochargers

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

C) On the shaft between the compressor side and the bearing housing

B) On the exhaust manifold to support the turbocharger housing

A) Between the compressor wheel and the turbine wheel

D) At the intake manifold to reduce air pressure fluctuations

8 / 12

3. Impact on Engine Performance

Question: How does a turbocharger affect the performance of a diesel engine?

B) It increases the engine's power output by compressing more air into the cylinders

C) It decreases the engine's fuel consumption by burning less fuel

A) It reduces the engine's power output by restricting airflow

D) It slows down the engine's RPM by increasing the exhaust back pressure

9 / 12

2. Impact of Air Cooler on Engine Performance

Question: How does an air cooler improve the performance of a diesel engine when fitted after a turbocharger?

C) By filtering out impurities from the intake air before it enters the engine

B) By slowing down the engine's RPM and reducing wear

A) By reducing fuel consumption and increasing power output

D) By preventing the turbocharger from overheating during operation

10 / 12

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

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

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

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

11 / 12

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

A) To provide additional lubrication to the turbocharger bearings

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

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

12 / 12

5. Faulty Wastegate or Boost Control Valve

Question: What routine maintenance can be performed to address a faulty wastegate or boost control valve?

B) Replace the wastegate or boost control valve with a new one

C) Adjust the engine's air-fuel ratio

D) Change the engine coolant

A) Inspect and clean the wastegate and boost control valve, and check for proper operation

Your score is