Car Tuning Car Maintenance 2 — Questions and Answers
Question 1: What does a mechanic mean when they say your brake rotors are 'below minimum thickness'?
- The rotors need resurfacing only
- The rotors must be replaced immediately (Correct answer)
- The rotors can be used for another 10,000 miles
- The rotors need more brake fluid
Correct answer: The rotors must be replaced immediately
Rotors below minimum thickness cannot safely dissipate heat and may warp or crack under braking stress.
Question 2: Which symptom most strongly indicates worn CV axle boots on a front-wheel-drive car?
- Vibration at highway speeds
- Clicking or popping noise when turning (Correct answer)
- Squealing during braking
- Rough idle at startup
Correct answer: Clicking or popping noise when turning
Torn CV boots allow grease to escape and dirt to enter, causing the clicking sound characteristic of a failing CV joint.
Question 3: When should you replace your car's cabin air filter?
- Every 3,000 miles
- Every 15,000–25,000 miles or annually (Correct answer)
- Only when the AC stops working
- Every 50,000 miles
Correct answer: Every 15,000–25,000 miles or annually
Most manufacturers recommend replacing the cabin air filter every 15,000–25,000 miles to maintain HVAC airflow and air quality.
Question 4: What is the purpose of a PCV (Positive Crankcase Ventilation) valve?
- It regulates fuel pressure
- It vents harmful crankcase gases back into the intake manifold (Correct answer)
- It controls engine oil pressure
- It manages transmission fluid flow
Correct answer: It vents harmful crankcase gases back into the intake manifold
The PCV valve routes combustion blowby gases from the crankcase back into the intake to be burned rather than vented to atmosphere.
Question 5: How can you verify that your car's thermostat is functioning correctly?
- Check that the engine never overheats
- Confirm the temperature gauge reaches normal operating range and stabilizes (Correct answer)
- Ensure the heater blows cold air
- Check that the radiator fan runs constantly
Correct answer: Confirm the temperature gauge reaches normal operating range and stabilizes
A working thermostat allows the engine to reach normal operating temperature quickly and hold it steady.
Question 6: What is the correct way to check automatic transmission fluid on most vehicles?
- Check it cold with the engine off
- Check it warm with engine running in Park or Neutral (Correct answer)
- Check it only at a service center
- Drain a small sample and test with a strip
Correct answer: Check it warm with engine running in Park or Neutral
ATF expands with heat, so most dipstick checks require the fluid to be at operating temperature with the engine running.
Question 7: Why is it important to replace fuel injectors that are leaking internally?
- They reduce oil pressure
- They cause fuel to drip into cylinders, fouling plugs and washing oil from cylinder walls (Correct answer)
- They increase exhaust back-pressure
- They reduce alternator output
Correct answer: They cause fuel to drip into cylinders, fouling plugs and washing oil from cylinder walls
Leaking injectors deliver excess fuel that washes the protective oil film from cylinder walls and contaminates the oil.
Car Tuning Car Maintenance 2
What does a mechanic mean when they say your brake rotors are 'below minimum thickness'?