Car Tuning Car Maintenance 5

Question 1

What does 'pinging' or 'knocking' from an engine typically indicate?

Accepted Answer

Detonation caused by low-octane fuel or incorrect ignition timing

Answer

Engine knock is caused by uncontrolled combustion (detonation) that can damage pistons and bearings if not corrected.

Question 2

Why is it important to use the correct viscosity motor oil in a turbocharged engine?

Accepted Answer

Turbo bearings require proper oil flow rate; wrong viscosity starves or floods them

Answer

Turbocharger bearings spin at extremely high RPM and depend on precisely metered oil film; incorrect viscosity disrupts this and accelerates bearing wear.

Question 3

What is the most accurate way to measure remaining brake pad thickness?

Accepted Answer

Use a caliper or ruler to measure the pad friction material directly

Answer

Direct measurement with a caliper gives exact remaining thickness, while the squeal indicator only triggers near the replacement threshold.

Question 4

Which condition can cause a car's fuel economy to drop noticeably without triggering a check engine light?

Accepted Answer

Both B and C are correct

Answer

Underinflated tires and a stuck-open thermostat both reduce fuel economy but may not set diagnostic trouble codes.

Question 5

What maintenance step should be performed after installing a new high-flow air filter on a modified engine?

Accepted Answer

Reset the ECU and re-tune or check MAF calibration

Answer

Changing airflow characteristics alters the MAF sensor signal, so a tune or at minimum an ECU reset and adaptation period is needed for proper fueling.

Car Tuning Practice Test

Car Tuning Practice Test

Car Tuning Car Maintenance 5