Deck 5: Intake and Exhaust Systems

Question 1

In the turbocharger compressor housing, what converts high velocity air into compressed air?

A) Compressor wheel.
B) Turbine wheel.
C) Restricted flow area.
D) Intake manifold.

Answer 1

C

Question 2

What is the function of air intake precleaners?

A) Sterilize intake air.
B) Filter heavier particulates from air in dusty environments.
C) Remove lighter particulates from intake air.
D) Remove moisture and dust from intake air.

Answer 2

B

Question 3

What is a typical maximum turbocharger rpm in most diesel engines?

A) 1,000,000 rpm
B) 140,000 rpm
C) 1,400,000 rpm
D) 14,000 rpm

Answer 3

B

Question 4

What component cools turbocharger boost air?

A) Charge air cooler (CAC)
B) Turbocharger impeller.
C) Diesel particulate filter (DPF)
D) Wet air filter.

Question 5

Name two types of charge air coolers:

A) Air to air and aftercoolers/intercoolers.
B) Ambient and pressurized.
C) High efficiency and low efficiency.
D) Wet and dry.

Question 6

Why has turbocharging become a requirement for most diesel engines?

A) To keep up with gasoline engines.
B) To meet market demand for more powerful engines.
C) Turbocharging simplifies the intake system.
D) To meet fuel efficiency requirements and emissions standards.

Question 7

What is the role of the intake system?

A) Deliver fuel to the engine.
B) Mix fuel and air/dead gas for combustion.
C) Create high pressures required for compression ignition.
D) Supply a charge of air or air/dead gas to the cylinders.

Question 8

What are the common methods of controlling wastegates?

A) Electronic and solenoid controlled.
B) Manifold pressure and PCM controlled solenoid.
C) Full-flow and bypass.
D) Variable gate and constant gate.

Question 9

What system are EGRs and DPFs part of?

A) Fuel system.
B) Intake circuit
C) Breathing circuit
D) Exhaust circuit.

Question 10

What is the typical maximum air inlet restriction pressure on a boosted engines?

A) 5inH2O vacuum
B) 50inH2O vacuum
C) 15inH2O vacuum
D) 25 inH2O vacuum

Question 11

Name two categories of turbochargers?

A) Turbines and compressors
B) Westegate and Volute
C) Electronic and mechanical.
D) Constant and variable geometry.

Question 12

What is the role of the exhaust system?

A) Minimize engine noise and harmful exhaust emissions.
B) The exhaust system maximizes engine horse power.
C) Control the amount of charge air entering and exiting the engine.
D) To cool exhaust to a safe level before it leaves the tail pipe.

Question 13

What type of VG turbochargers are used by most current diesel engine OEMs?

A) Wastegate controlled.
B) Constant volute.
C) Variable volute.
D) Constant geometry (CG).

Question 14

Why is exhaust gas recirculation (EGR) used?

A) To meet emissions standards.
B) To increase fuel efficiency.
C) To regulate charge air temperature.
D) To increase engine horsepower.

Question 15

What recently introduced valve management technology enables compression ratio management?

A) Non-lashing valves.
B) Valve rotators.
C) Variable Valve Timing (VVT).
D) Valve harmonics.

Question 16

Which of the following specifications is most critical in making an on-engine determination of turbine shaft wear?

A) Turbine shaft diameter.
B) Turbine shaft length.
C) Turbine shaft radial play.
D) Thrust bearing inner diameter.

Question 17

Most post-2010 diesel engines require what type of fluid for emissions control?

A) Exhaust aftertreatment fluid (EAF).
B) Diesel particulate fluid (DPF).
C) CARB emissions fluid.
D) Diesel exhaust fluid (DEF).

Question 18

What is the main determining factor in turbocharger RPM?

A) Exhaust gas temperature.
B) Turbocharger geometry.
C) Compressor wheel design.
D) Exhaust gas pressure.

Question 19

What manages the breathing circuit on current certified highway diesel engines?

A) The chassis control module (CCM).
B) Mechanical actuators and sensors.
C) Powertrain control module (PCM).
D) EGR control module.

Question 20

Technician A states mufflers are no longer required on vehicles manufactured after 2010 and can be replaced with a straight exhaust pipes. Technician B states it is illegal to tamper with or modify emission control devices. Which technician is correct?

A) Technician A only.
B) Technician B only.
C) Both A and B.
D) Neither A nor B.

Question 21

Technician A states precleaners are used on work trucks that operate in dusty conditions such as construction or agriculture. Technician B states precleaners can triple the service life of the main engine air filter. Which technician is correct?

A) Technician A only.
B) Technician B only.
C) Both A and B.
D) Neither A nor B.