Search Symptoms
Describe what your car is doing and find the most relevant guide or diagnostic path.
Start with what you notice: noise, smell, warning light, vibration, starting trouble, overheating, or loss of power.
42 symptoms
Car Won't Start
Dead battery, starter, fuel pump, or immobiliser — diagnose in the right order.
Engine Overheating
Pull over immediately — severe damage occurs within minutes above the red zone.
Oil Pressure Warning Light
Stop the engine now — low oil pressure destroys bearings fast.
Brake Noise — Squealing or Grinding
Grinding metal-on-metal means pad material is gone — do not drive.
Transmission Slipping or Hesitating
Complete loss of drive may be imminent — address before highway travel.
Engine Noise — Knocking or Ticking
A knock under load may mean imminent bearing failure — check oil first.
Exhaust Smoke — White, Blue, or Black
Smoke color tells you whether it's coolant, oil, or fuel that's burning.
Engine Misfire
Worn plugs, failing coils, or vacuum leaks — an OBD2 scan identifies the cylinder.
Check Engine Light Flashing
A flashing light is an emergency — pull over safely; active misfires destroy the catalytic converter within minutes.
Hesitation When Accelerating
Flat spots, stumbles, or hesitation under throttle — usually MAF, fuel, or ignition delivery.
Car Won't Start — Clicking Noise
Single click or rapid clicking on key turn — almost always a discharged battery, terminals, or starter.
Engine Cranks But Won't Start
Starter spins normally but the engine never fires — usually missing spark, fuel, or a sensor signal.
White Smoke From Exhaust
Brief vapor on cold start is normal; persistent thick white smoke usually means coolant in the combustion chamber.
Blue Smoke From Exhaust
Blue or blue-grey exhaust smoke means engine oil is being burned — valve seals, rings, PCV, or turbo seals.
Gas Smell From Car
Loose gas cap, EVAP leak, or fuel line issue — check the cap first, then scan for EVAP codes.
Check Engine Light On
Solid light: drive to a shop. Flashing light: stop driving immediately.
Rough Idle
Spark plugs, vacuum leaks, or a dirty throttle body — a scanner narrows it fast.
Engine Shaking or Vibrating
Misfires and broken engine mounts are the most common causes.
Poor Acceleration
Air, fuel, or ignition restriction — start with the air filter and OBD2 scan.
Shaking When Braking
Warped rotors or uneven pad deposits — the pedal pulsation confirms it.
Car Stalling or Cutting Out
Stalling at junctions or speed is a genuine safety risk — diagnose promptly.
Battery Slow Crank or Slow Start
A warning before total failure — test the battery before cold weather hits.
Battery Drains Overnight
A parasitic drain from a relay, module, or accessory is the usual culprit.
Tire Pressure Keeps Dropping
Slow puncture, valve stem, or bead-seat leak — soapy water finds it fast.
Vibration at Highway Speeds
Usually tire balance or a bent rim — check lug nuts first.
Car Pulls to One Side
Tire pressure, alignment, or a seized caliper — check pressure first.
Hard to Steer or Power Steering Failure
Fluid level, belt, or EPS fault — sudden heavy steering requires immediate attention.
Steering Wheel Shakes While Driving
Wheel balance and tire condition are the fastest things to rule out.
Clicking Noise When Turning
A worn CV joint on front-wheel-drive vehicles is the most common cause.
Brakes Squealing
Morning-only squeal is usually rust; every-stop squeal means worn pads.
Brake Squeal
Wear indicator tabs, glazed rotors, or missing anti-squeal shims.
Squealing Belt Noise
A worn or slipping serpentine belt — failure disables steering and charging.
Loss of Power
Clogged cat, MAF sensor, or fuel delivery issue — an OBD2 scan narrows it fast.
Rotten Egg Smell From Exhaust
Failing catalytic converter or rich-running engine — scan for P0420 first.
Hard Starting
Fuel pump, crank sensor, or worn plugs — try double-priming the fuel pump first.
Car Stalls When Idling
Dirty throttle body, vacuum leak, or failing idle control — clean the throttle first.
Reduced Acceleration
Clogged cat, dirty MAF, or weak fuel pump — check for limp mode with an OBD2 scan.
Heater Not Working
Low coolant or a stuck thermostat are the first two things to check.
AC Not Cooling
Low refrigerant, a failed compressor clutch, or a blocked cabin filter.
Poor Fuel Economy
Dirty O2 sensor, clogged air filter, or low tire pressure — scan for codes first.
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