Car problem finder
Pick a symptom to see the likely causes, the checks to run and the tools you need — then start the interactive diagnostic to narrow it down.
Car will not start
The engine turns or clicks but will not fire. The cause is usually battery, starter, fuel or ignition — tested in a precise order.
See causes & checks →Engine overheats
Overheating is a warning you must not ignore. Find the cause before it damages the engine.
See causes & checks →Black smoke from the exhaust
Black smoke is unburned fuel — the mixture is too rich.
See causes & checks →White smoke from the exhaust
White smoke can be harmless condensation — or serious coolant burning.
See causes & checks →Loss of power
The car feels flat. Power loss usually comes from boost, fuel, ignition or a dragging brake.
See causes & checks →Vibration while driving
Vibration tells you where to look by when it happens: at speed, braking, idling or accelerating.
See causes & checks →Check engine light on
The light means the ECU stored a code. Steady is usually sensor/emissions; flashing is a severe misfire.
See causes & checks →High fuel consumption
A sudden jump in consumption usually has a physical cause; a gradual rise is often maintenance.
See causes & checks →Weak or spongy brakes
Never delay on brakes. A soft pedal, sinking pedal or long stopping distance needs attention now.
See causes & checks →Air conditioning not cooling
The AC not cooling usually points to gas level, the compressor clutch, or airflow.
See causes & checks →Hard starting / long cranking
Long cranking means the engine needs more of something: fuel pressure, spark, battery or compression.
See causes & checks →Not sure where to start?
Use the interactive diagnostic — it asks targeted questions and ranks the likely causes for you.