Auto Information
What to know
Auto Information tests how a car works and how to keep it running. The centerpiece is the four-stroke cycle: intake (air and fuel enter), compression (the piston squeezes the mixture), power (the spark ignites it and drives the piston down), and exhaust (gases leave).
Know the major systems: fuel and air intake, ignition, cooling (radiator, thermostat, water pump, coolant), lubrication (oil pump, oil filter), exhaust, electrical (battery, starter, alternator), brakes (disc and drum), steering and suspension, and drivetrain (clutch or torque converter, transmission, differential).
Routine maintenance facts appear often: check tire pressure cold, rotate tires, change oil and filter on schedule, replace brake pads before metal contacts metal, and never open a hot radiator.
Traps
- Confusing the battery's job (storing charge, cranking) with the alternator's (charging while the engine runs).
- Mixing up coolant and oil functions. Coolant carries heat away; oil lubricates and also helps cool moving parts.
- Assuming a car that cranks but will not start has a dead battery. Cranking proves the battery and starter work.
Rule of thumb
Diagnose by symptom. No crank points to battery, cables, or starter; a single click points to the solenoid or connections; cranking without firing points to fuel, spark, or timing.
Worked example
An engine overheats after ten minutes of driving. Coolant is low and the upper radiator hose stays cold. A cold upper hose suggests a thermostat stuck closed, blocking coolant flow to the radiator. Topping off coolant without replacing the thermostat only repeats the failure.