CAA Automotive Systems and Parts 4 — Questions and Answers
Question 1: Which engine component converts the reciprocating motion of the pistons into rotational motion?
- Camshaft
- Crankshaft (Correct answer)
- Timing belt
- Connecting rod bearing
Correct answer: Crankshaft
The crankshaft turns the up-and-down movement of the pistons, delivered through connecting rods, into rotation.
Question 2: Failure of a timing belt on an interference engine typically results in what?
- Only a no-start condition with no internal damage
- Loss of power steering only
- Overheating from loss of coolant flow
- Valves contacting pistons, causing major engine damage (Correct answer)
Correct answer: Valves contacting pistons, causing major engine damage
In an interference engine, valve and piston paths overlap, so belt failure lets them collide and bend valves.
Question 3: When appraising a 4WD vehicle, which component lets the driver select between two-wheel and four-wheel drive?
- Transfer case (Correct answer)
- Differential
- Torque converter
- Driveshaft U-joint
Correct answer: Transfer case
The transfer case splits power between the front and rear axles and lets the driver choose drive modes.
Question 4: What is the function of a differential in a vehicle's drivetrain?
- Change gear ratios for speed
- Connect the engine to the transmission
- Allow drive wheels to rotate at different speeds during turns (Correct answer)
- Absorb road shock
Correct answer: Allow drive wheels to rotate at different speeds during turns
The differential lets the outer wheel travel faster than the inner wheel when cornering.
Question 5: Which part supports the rotating drive wheel hub and, when worn, produces a humming noise that changes with vehicle speed?
- Tie rod end
- Ball joint
- Sway bar link
- Wheel bearing (Correct answer)
Correct answer: Wheel bearing
Worn wheel bearings create a growl or hum that increases with speed and often changes when turning.
Question 6: A hybrid vehicle's high-voltage battery condition is important to its appraisal because:
- It is rarely replaced and costs little
- It only powers the radio and lights
- Replacement is costly and battery health strongly affects market value (Correct answer)
- It has no effect on fuel economy
Correct answer: Replacement is costly and battery health strongly affects market value
Hybrid and EV traction batteries are expensive to replace, so their state of health significantly affects value.
Question 7: Which component in a modern ignition system replaced the distributor by providing a dedicated coil for each cylinder?
- Coil-on-plug ignition (Correct answer)
- Points and condenser
- Ballast resistor
- Magneto
Correct answer: Coil-on-plug ignition
Coil-on-plug systems mount an individual coil on each spark plug, eliminating the distributor and plug wires.
CAA Automotive Systems and Parts 4
Which engine component converts the reciprocating motion of the pistons into rotational motion?