What’s your car doing?

Pick what you see, hear, smell, or feel. You will get the likely causes first. Causes are listed most common first. You will get safe checks you can do yourself. You will get a clear answer: is it safe to drive, or not? Go one step at a time. You do not need car knowledge.

Not sure? Answer a few questions

Tap the problem that sounds closest. Then answer one question at a time. Each question has yes-or-no style answers. It takes about a minute.

No match for that. Try a simpler word. Try “noise”. Try “leak”. Try “start”. Try “smoke”. Try “brake”. Or use the questions above. The page will narrow it down for you.

Dashboard warning lights, in plain words

Red means stop. Yellow or orange means get it checked soon. Green and blue just tell you something is switched on.

OIL

Oil pressure — red

The engine has lost oil pressure. Oil pressure is the force that pushes oil through the engine. Turn the engine off right away. Do not run it. Even one minute can ruin the engine. Wait for the engine to cool. Then check the oil level. If the oil level looks fine, do not drive. Call for a tow.

TEMP

Temperature — red

The engine is too hot. Pull over. Turn the engine off. Wait at least 30 minutes. Let it cool. Never open the radiator cap while it is hot. The radiator cap is the cap on the cooling system. Hot steam can burn you badly.

BRAKE

Brake — red

First, check the parking brake. Make sure it is fully off. If the light stays on, brake fluid may be low. Brake fluid is the fluid that makes the brakes work. There may be a brake fault. Test the pedal with a gentle push before you move. If the pedal feels soft, do not drive.

BATT

Battery / charging — red

The car is running on battery power only. This is often a failed alternator. The alternator is the part that makes power while the engine runs. A broken belt can also cause it. You may have 20 to 30 minutes of driving before the car dies. Drive straight to a shop or a safe place. Turn the lights off. Turn the A/C off.

CHECK
ENG

Check engine — yellow

If the light stays on and does not flash, the computer found a fault. The computer is the car’s control box. It is usually safe to drive gently. Drive to a shop or parts store. Ask for a free code reading. A code is a number that names the fault. If the light flashes, stop soon. The engine is misfiring. Misfiring means the engine is skipping beats. It can damage the catalytic converter. The catalytic converter is a part that cleans the exhaust.

ABS

ABS — yellow

ABS means anti-lock brakes. This system stops the wheels from locking in a hard stop. Your normal brakes still work. But the anti-lock part is off. The wheels can lock if you brake hard. Drive gently. Leave more space in front of you. Get it checked.

TIRE
!

Tire pressure — yellow

One or more tires is low on air. Stop at the next safe place. Check all four tires with a gauge. A gauge is a small tool that measures air pressure. Fill each tire to the number on the driver’s door sticker. Do not use the number on the tire. If a tire is very flat, stop. Use the spare tire.

AIR
BAG

Airbag — yellow

The airbag system has a fault. The airbag may not work in a crash. The car drives normally. Still, get it fixed. This is about your safety. It is not about the engine.

What color is the puddle?

Put a piece of white cardboard under the car. Leave it there overnight. Look at it in the morning. The color tells you a lot. The spot tells you a lot too. Note where it is. Is it at the front? Is it in the middle? Is it at the back?

Red or pink

Transmission fluid or power steering fluid. Transmission fluid is the fluid for the gears that move the car. Power steering fluid is the fluid that helps you turn the wheel. This fluid feels slippery. Low fluid can damage the transmission. Get it looked at soon. If the spot is near the middle of the car, it is usually transmission fluid. If the spot is near the front, check the power steering fluid.

Green, orange, or pink — sweet smell

Coolant. Coolant is also called antifreeze. It is the fluid that keeps the engine cool. It feels a bit slimy. It smells sweet. Coolant is poisonous to pets. Wipe it up. Do not ignore a steady leak. A steady leak can make the engine get too hot.

Dark brown or black

Engine oil. This is the most common leak. Check the oil level. Use the dipstick. The dipstick is the thin metal stick you pull out to check oil. A few drops is a “watch it” problem. A growing puddle means see a shop. A fast drop on the dipstick also means see a shop.

Light brown or amber, very slippery

Brake fluid. Look near a wheel. Look under the brake pedal area. Treat this as serious. A brake fluid leak can make the brakes fail. Do not drive it. Call for a tow.

Clear and thin, like water

Usually just air-conditioning water. This is normal on hot days. You will see it under the passenger side. But smell it. If it smells strongly like gas, it is fuel. Do not drive. Do not smoke nearby. Call for help.

For Mark — your 2010 Mercury Grand Marquis

This car is known for a few weak spots. Learn them now. You can spot them early. The engine is a 4.6L V8. It is tough. It lasts a long time. Most trouble comes from parts around the engine. The engine itself is rarely the problem.

Known weak spots on this model

  • The back of the car sits low. Or it sags overnight. Many of these cars have rear air suspension. Air suspension uses air bags instead of metal springs to hold the car up. Sagging often means an air spring leaks. An air spring is one of those air bags. Or the compressor is tired. The compressor is the pump that fills the air bags. The common fix is to fit new air springs. Or fit regular coil springs instead. Coil springs are metal springs. Many owners do that once. Then they never touch it again.
  • Coolant leaks near the front of the engine. The intake manifold has plastic parts that carry coolant. The intake manifold is the part that brings air into the engine. Those plastic parts can crack with age and heat. Look for two signs together. One: a sweet smell. Two: the coolant level drops slowly.
  • Headlights go out while you drive. A relay inside the lighting control module wears out on these cars. A relay is a small electric switch. The lighting control module is the box that controls the lights. If the headlights stop but the parking lights still work, suspect that module first. Check it before you buy new bulbs.
  • A window stops going up or down. The window regulators wear out on these cars. A window regulator is the part that moves the glass up and down. You may hear the motor run. But the glass stays still. That is the sign.
  • Good news: Parts for this car are cheap. Parts are easy to find. Almost any shop knows this car. The same basic car was used for years as Crown Victoria police cars and taxis.

Safe checks you can do yourself

Each check takes about five minutes. You need no tools, except where a step says so. Keep the engine off. Keep the engine cool. Do that unless a step says otherwise.

Check the engine oil

Park on flat ground. Turn the engine off. Wait 5 minutes.

  1. Pull the dipstick out. The dipstick is the thin metal stick you use to check oil.
  2. Wipe the dipstick clean.
  3. Push the dipstick all the way back in.
  4. Pull the dipstick out again.
  5. Look at the oil. The oil should sit between the two marks.
  6. If the oil is low, add oil. Use the oil type written on the oil cap.
  7. Add only a little at a time.
  8. Check the level again.
  9. If the oil is black and feels gritty, see a shop.
  10. If the oil looks like chocolate milk, see a shop.

Check the coolant

Do this only when the engine is fully cool.

  1. Find the coolant tank. It is a see-through plastic tank.
  2. Do not open the radiator itself.
  3. Look at the side of the tank.
  4. The level should sit between MIN and MAX.
  5. If the level is low, add coolant. Use the type in your owner’s manual.
  6. If you have no coolant and you must get to a shop, plain water can get you there.
  7. If the level keeps dropping, there is a leak.
  8. Find the leak before the engine gets too hot.
  9. If you cannot find the leak, call a mechanic.

Look at the battery

Turn the engine off. You need no tools for a look.

  1. Look at the battery terminals. Terminals are the posts where the cables join the battery.
  2. Look for white crust or green crust on the terminals.
  3. That crust causes many no-starts.
  4. Grab one cable with your hand.
  5. Try to wiggle it.
  6. Do the same with the other cable.
  7. A cable should not move. If a cable moves, you found a problem.
  8. Cables should be tight.
  9. Cables should be clean.
  10. If you are not sure, go to a parts store. Most parts stores test the battery for free.

Check tire pressure

You need a cheap tire gauge. A gauge is a small tool that measures air pressure.

  1. Find the sticker inside the driver’s door.
  2. Use the number on that sticker.
  3. Do not use the number on the tire.
  4. Check the tires when they are cold.
  5. Check before you drive.
  6. Check all four tires.
  7. Check the spare tire too.
  8. A flat spare is no spare at all.

Keep in the trunk

  • Jumper cables or a jump pack — cables or a small battery box that help start a dead battery
  • Tire gauge and the spare tire — check the spare
  • Flashlight with fresh batteries
  • Bottle of water — for you, and in a pinch for the radiator
  • Phone charger that plugs into the car
  • Reflective triangle or flares — bright warning signs to put behind the car
  • Work gloves and an old towel
  • A quart of the right engine oil
  • Basic wrench and screwdriver set
  • Paper copy of your insurance and roadside number