NYC Auto Mechanic Exam Full Practice
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of engine oil?
A. Cool the engine
B. Clean the fuel system
C. Lubricate moving engine parts
D. Increase compression
Correct answer: Engine oil reduces friction and wear between moving
engine components, helping prevent overheating and damage.
2. Which component controls the amount of air entering the engine?
A. Fuel injector
B. Intake manifold
C. Throttle body
D. Exhaust valve
Correct answer: The throttle body regulates airflow into the engine
based on accelerator input.
,3. A weak battery is most likely to cause which symptom?
A. Engine overheating
B. Slow or no engine cranking
C. Excessive fuel consumption
D. Knocking noise
Correct answer: Insufficient battery voltage prevents the starter from
turning the engine properly.
4. What does an alternator do?
A. Starts the engine
B. Stores electrical energy
C. Charges the battery and powers electrical systems
D. Controls ignition timing
Correct answer: The alternator converts mechanical energy into
electrical energy while the engine runs.
5. Which system reduces harmful exhaust emissions?
A. Cooling system
B. Fuel system
C. Emission control system
D. Ignition system
Correct answer: Emission control components like catalytic
converters reduce pollutants.
6. What is the function of a catalytic converter?
A. Increase engine power
, B. Reduce engine noise
C. Convert harmful gases into less harmful emissions
D. Improve fuel mileage
Correct answer: Catalytic converters chemically change toxic exhaust
gases into safer compounds.
7. Which tool is best for tightening bolts to a specific torque?
A. Breaker bar
B. Adjustable wrench
C. Torque wrench
D. Ratchet
Correct answer: A torque wrench ensures fasteners are tightened to
manufacturer specifications.
8. What does ABS stand for?
A. Automatic Braking System
B. Anti-lock Braking System
C. Advanced Brake Sensor
D. Assisted Brake System
Correct answer: ABS prevents wheel lockup during hard braking.
9. Brake fluid should be replaced because it:
A. Evaporates
B. Turns acidic
C. Absorbs moisture over time
D. Loses color
, Correct answer: Moisture lowers boiling point and reduces braking
efficiency.
10. Which component converts hydraulic pressure into mechanical
braking force?
A. Master cylinder
B. Brake caliper
C. Brake pedal
D. Proportioning valve
Correct answer: The caliper presses brake pads against the rotor to
slow the vehicle.
11. What is the main purpose of engine coolant?
A. Lubricate engine parts
B. Regulate engine temperature
C. Clean the radiator
D. Prevent fuel freezing
Correct answer: Coolant absorbs and transfers heat to prevent
overheating.
12. A thermostat stuck closed will cause:
A. Engine runs cool
B. Engine overheating
C. Poor fuel economy
D. Battery drain
Questions And Correct Answers
(Verified Answers) Plus Rationales 2026
Q&A | Instant Download Pdf
1. What is the primary function of engine oil?
A. Cool the engine
B. Clean the fuel system
C. Lubricate moving engine parts
D. Increase compression
Correct answer: Engine oil reduces friction and wear between moving
engine components, helping prevent overheating and damage.
2. Which component controls the amount of air entering the engine?
A. Fuel injector
B. Intake manifold
C. Throttle body
D. Exhaust valve
Correct answer: The throttle body regulates airflow into the engine
based on accelerator input.
,3. A weak battery is most likely to cause which symptom?
A. Engine overheating
B. Slow or no engine cranking
C. Excessive fuel consumption
D. Knocking noise
Correct answer: Insufficient battery voltage prevents the starter from
turning the engine properly.
4. What does an alternator do?
A. Starts the engine
B. Stores electrical energy
C. Charges the battery and powers electrical systems
D. Controls ignition timing
Correct answer: The alternator converts mechanical energy into
electrical energy while the engine runs.
5. Which system reduces harmful exhaust emissions?
A. Cooling system
B. Fuel system
C. Emission control system
D. Ignition system
Correct answer: Emission control components like catalytic
converters reduce pollutants.
6. What is the function of a catalytic converter?
A. Increase engine power
, B. Reduce engine noise
C. Convert harmful gases into less harmful emissions
D. Improve fuel mileage
Correct answer: Catalytic converters chemically change toxic exhaust
gases into safer compounds.
7. Which tool is best for tightening bolts to a specific torque?
A. Breaker bar
B. Adjustable wrench
C. Torque wrench
D. Ratchet
Correct answer: A torque wrench ensures fasteners are tightened to
manufacturer specifications.
8. What does ABS stand for?
A. Automatic Braking System
B. Anti-lock Braking System
C. Advanced Brake Sensor
D. Assisted Brake System
Correct answer: ABS prevents wheel lockup during hard braking.
9. Brake fluid should be replaced because it:
A. Evaporates
B. Turns acidic
C. Absorbs moisture over time
D. Loses color
, Correct answer: Moisture lowers boiling point and reduces braking
efficiency.
10. Which component converts hydraulic pressure into mechanical
braking force?
A. Master cylinder
B. Brake caliper
C. Brake pedal
D. Proportioning valve
Correct answer: The caliper presses brake pads against the rotor to
slow the vehicle.
11. What is the main purpose of engine coolant?
A. Lubricate engine parts
B. Regulate engine temperature
C. Clean the radiator
D. Prevent fuel freezing
Correct answer: Coolant absorbs and transfers heat to prevent
overheating.
12. A thermostat stuck closed will cause:
A. Engine runs cool
B. Engine overheating
C. Poor fuel economy
D. Battery drain
