Red, amber and green
Dashboard lights roughly follow a traffic-light scheme. Red usually means stop or act now. Amber or yellow usually means something needs attention soon. Green or blue usually just means a system is on. Your owner's manual explains every symbol for your vehicle; keep it in the glove box or download it from the maker.
Lights that mean stop safely
- Oil pressure. The engine may not be getting enough oil. Pull over safely and switch off the engine. Driving on can destroy it.
- Engine temperature. The engine is overheating. Pull over, switch off and let it cool. Don't open a hot radiator cap.
- Red brake light. Possibly low brake fluid or a brake system fault (or the parking brake is on). Check the parking brake; if the light stays on, get the car checked before driving far.
- Charging system or battery. The alternator may not be charging. The car will run on battery for a limited time, then stop.
Lights that mean get it checked
- Check engine, steady. Something in the engine or emissions system has a fault. Get it diagnosed soon.
- Check engine, flashing. Usually a serious misfire that can damage the catalytic converter. Slow down and get it checked as soon as you safely can.
- ABS. The anti-lock system has a fault; normal braking usually still works.
- Tire pressure. One or more tires may be low. Check pressures when the tires are cold.
- Airbag. The airbag system has a fault and may not deploy in a crash.
Noises
- Squeal at startup or when turning the wheel. Often a worn or loose drive belt.
- Squeal when braking. Often the brake pad wear indicator.
- Grinding when braking. Metal on metal; pads may be gone.
- Clicking when turning. On front-wheel-drive cars, often a worn outer CV joint.
- Clunk over bumps. Worn suspension parts such as links, bushings or ball joints.
- Hum or whine that rises with speed. Often a wheel bearing, sometimes tires or the differential.
- Rattle at startup. On some engines, a timing chain or tensioner.
- Hissing under the hood. A vacuum leak, or coolant escaping from a hot system.
Smells
- Sweet, syrupy. Coolant leaking, possibly inside the cabin from the heater core.
- Burning oil. Oil leaking onto hot exhaust parts.
- Rotten eggs. Often related to the catalytic converter or fuel mixture.
- Hot, acrid smell after hard braking. Overheated brakes, or a sticking caliper.
- Gasoline. A fuel leak. Don't ignore it; get it checked promptly.
Leaks under the car
Put a piece of cardboard under the engine overnight and look at the color:
- Clear water near the front passenger side on a hot day: usually air conditioning condensation, which is normal.
- Brown or black: engine oil.
- Red or reddish-brown: often automatic transmission fluid or power steering fluid.
- Green, orange, pink or yellow and slightly sweet: coolant.
- Blue: windshield washer fluid.
- Clear to amber and slick, near a wheel: possibly brake fluid. Get it checked before driving.
Vibrations
- Shaking at highway speed that gets better or worse with speed. Often tire balance, a damaged tire or a bent wheel.
- Shaking only when braking. Usually rotor problems.
- Shaking at idle. Possibly a misfire or a worn engine mount.
Note the speed where it starts and stops; it helps the shop narrow it down.
How it drives
Pulling to one side, a vibration at certain speeds, a soft brake pedal, or a car that hesitates or surges are all worth mentioning to a shop, with notes on when they happen.
Tell the shop what you noticed
Write down what you see, hear and smell, and when: cold or warm, braking or accelerating, turning or straight, at what speed. A clear description can save diagnostic time and money.