Deck 7: Intake and Exhaust Systems

Question 1

Technician A says that the air cleaner assembly has a bypass valve that allows air into the engine when the air filter is clogged. Technician B says that most air filters are mounted after the MAF. Who is correct?

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

Answer 1

D

Question 2

All of the following are true about turbochargers EXCEPT ____.

A) they increase engine power
B) they are lubricated by pressurized engine oil
C) they provide maximum horsepower increase just above idle
D) some are cooled by engine coolant

Answer 2

C

Question 3

Faulty turbochargers can cause excessive amounts of oil to be leaked into the exhaust system.

Answer 3

True

Question 4

Which of the following would be considered a vacuum at sea level?

A) 12 psia
B) 14.7 psia
C) 10 psig
D) 0 psig

Question 5

A digital pyrometer is used to measure the amount of oxygen and carbon monoxide in the exhaust system.

Question 6

Some air cleaner assemblies have a flow restriction indicator that indicates when the air filter needs servicing.

Question 7

Technician A says that an engine developing 10" of vacuum at idle is a normal condition. Technician B says that engines with clogged exhaust systems will have more than 20" of vacuum when under throttle. Who is correct?

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

Question 8

Turbochargers are driven by a belt attached to the crankshaft of the engine.

Question 9

1999 and new model year cars have sensors to indicate the efficiency of the catalytic converter.

Question 10

Turbochargers are being discussed. Technician A says that the engine supplies oil to the turbocharger for lubrication. Technician B says that all turbochargers have coolant lines from the engine attached to prevent overheating. Who is correct?

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

Question 11

Propane can be used to locate the sources of vacuum leaks.

Question 12

Technician A says that intercoolers are used in turbocharger systems to cool the turbo bearings. Technician B says that some intercoolers are water cooled. Who is correct?

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

Question 13

Dirty air filters should be cleaned with compressed shop air to restore original air flow.

Question 14

An air leak in the ductwork between the MAF sensor and the throttle plate could cause an engine to run too lean.

Question 15

Many intake system air ducts use a resonator to reduce noise generated within the ducts.

Question 16

Intake manifolds on engines may be made of plastic.

Question 17

Turbochargers are being discussed. Technician A says that the compressor wheel is mounted in the air intake system. Technician B says that boost pressure is limited by the wastegate. Who is correct?

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

Question 18

Technician A says that vacuum is high when engine load is high. Technician B says that vacuum is high when an engine is at idle speed and no load. Who is correct?

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

Question 19

Technician A says that engines with multi-port fuel injection use plastic intake manifolds to cool the air-fuel mixture. Technician B says that intake runners that are short and large in diameter are designed for peak power at lower engine rpm. Who is correct?

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

Question 20

Technician A says that engine vacuum is used to operate some emissions control devices. Technician B says that an EGR valve may be operated by engine vacuum. Who is correct?

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

Question 21

Leaking turbocharger seals can cause ____________________ exhaust smoke.

Question 22

Technician A says that exhaust leaks can affect the air-fuel mixture of an engine. Technician B says that exhaust leaks can be dangerous for customers driving their car. Who is correct?

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

Question 23

Testing for a restricted exhaust system using a vacuum gauge is being discussed. Technician A says this test should be performed at idle only. Technician B says that high vacuum on the gauge during all phases of the test indicated a restricted exhaust. Who is correct?

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

Question 24

A poorly or non-functioning catalyst will fail the ____________________ monitor on an OBD II vehicle.

Question 25

Technician A says that inadequate engine oil level can damage a turbocharger. Technician B says low engine oil level can cause damage to a supercharger. Who is correct?

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

Question 26

____________________ causes the internal parts of a turbocharger to rotate.

Question 27

Which of the following would most likely cause oil to be found in the air cleaner assembly?

A) blowby past the piston rings
B) clogged crankcase ventilation filter
C) damaged intake valve guide seal
D) stuck open PCV valve

Question 28

Intake manifolds are commonly made of ____________________ and ____________________ .

Question 29

The ____________________ , located in the exhaust system, is used to reduce pollution.

Question 30

Technician A says the catalytic converter helps reduce exhaust system noise. Technician B says a catalytic converter may be mounted into the exhaust manifold. Who is correct?

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

Question 31

Technician A says a broken vacuum line can cause an EGR system malfunction. Technician B says a broken vacuum line can affect turbocharger operation. Who is correct?

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

Question 32

Explain how you would use propane to find vacuum leaks.

Question 33

A cracked exhaust pipe before the upstream HO2S can cause all of the following except:

A) A lean HO2S signal
B) A rich air-fuel ratio
C) O2 sensor heater failure
D) Poor fuel economy

Question 34

The three-way catalytic converter is designed to reduce ____________________ , carbon ____________________ , and ____________________ of nitrogen.

Question 35

A vacuum gauge fluctuates rapidly between about 12 and 17 in. Hg. This could be an indication of:

A) Worn compression rings
B) Leaking head gasket
C) Burnt or sticking valves
D) Restricted exhaust system

Question 36

Two tools that can be used to test for exhaust restriction are the ____________________ and ____________________.

Question 37

An ____________________   malfunction from a turbocharger can cause serious engine damage.

Question 38

Technician A says that broken vacuum hoses can cause an engine to run lean. Technician B says that vacuum leaks can cause poor fuel economy. Who is correct?

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

Question 39

To help extend the life of a turbocharger, the customer should allow the engine to ____________________ for about ____________________ minute(s) before shutting the engine off.

Question 40

The ____________________ may need to be reset after an air filter replacement.

Question 41

Describe the use of a backpressure gauge to test the exhaust system.

Question 42

What are the benefits of combining a variable intake manifold with a variable valve timing system?

Question 43

What purpose does the wastegate on a turbocharger serve, and how does it work?

Question 44

Explain the use of a vacuum gauge when testing for a restricted exhaust system.

Question 45

Describe how to test boost pressure on a vehicle with a turbocharger and explain what the results could indicate.

Question 46

Some exhaust manifolds with machined surfaces do not require a gasket.