Car Diagnostics Guide
Your car talks to you through warning lights, sounds, and smells. Let's learn what it's saying!
Dashboard Warning Lights
When a light appears on your dashboard, don't panic! Here's what each one means and what to do.
Temperature Warning
Stop Driving!Your engine is getting too hot! This is one of the most serious warning lights.
What To Do
Pull over safely as soon as possible. Turn off the engine and wait for it to cool down completely. Do not open the radiator cap while it's hot! Call for help if the light doesn't go away.
Oil Pressure Warning
Stop Driving!Your engine oil pressure is too low. Driving without enough oil can seriously damage the engine.
What To Do
Stop the car safely as soon as you can. Check the oil level with the dipstick. If it's low, add oil. If the light stays on even after adding oil, call a mechanic.
Battery / Charging Alert
Check SoonThe battery isn't charging properly. Your car might run for a while but could stop eventually.
What To Do
Turn off things that use electricity (radio, AC, phone charger) to save power. Drive to a mechanic or auto store soon to get the battery and alternator checked.
Brake Warning
Stop Driving!Something might be wrong with your brakes. This could mean low brake fluid or worn brake pads.
What To Do
First, check if your parking brake is off (that's the most common cause!). If it is off and the light is still on, drive slowly to a mechanic right away. Brakes are your most important safety feature.
Check Engine Light
Check SoonThis is the most common warning light. It could mean many different things, from a loose gas cap to something more serious.
What To Do
First, try tightening your gas cap — that fixes it surprisingly often! If it stays on, visit an auto parts store where they can read the code for free. If the light is flashing, pull over and call for help.
Tire Pressure (TPMS)
Check SoonOne or more of your tires doesn't have enough air. Low tire pressure is bad for safety and gas mileage.
What To Do
Check all four tires with a pressure gauge. Fill any low tires to the recommended pressure (found on the sticker inside your driver's door). The light should turn off after driving a few miles.
Maintenance Required
Good to KnowIt's time for scheduled maintenance, like an oil change. This is based on mileage, not a problem.
What To Do
Schedule an oil change or other maintenance soon. This light is a helpful reminder, not an emergency. After the service is done, the mechanic will reset the light.
What's That Sound?
Strange noises can be your car's way of asking for help. Here's a guide to common car sounds and what they mean.
Squealing when braking
Likely cause: Worn brake pads
Brake pads have built-in metal tabs that squeal when the pads are getting thin. It's like a built-in alarm! Get them checked at a mechanic.
Grinding when braking
Likely cause: Brake pads completely worn
This means the brake pads have worn through completely and metal is grinding on metal. This is dangerous and needs immediate repair!
Clicking when turning
Likely cause: CV joint needs attention
The CV joint helps your wheels turn smoothly. Clicking usually means the protective boot has torn and the joint is wearing out. See a mechanic soon.
Engine knocking or pinging
Likely cause: Wrong fuel or engine issue
This can happen if you use the wrong type of gas. Try using the fuel grade recommended in your owner's manual. If it continues, see a mechanic.
Hissing under the hood
Likely cause: Coolant or vacuum leak
Hissing often means fluid is leaking onto something hot. Pull over safely and check for any visible leaks or steam. Don't touch anything hot!
Rattling underneath
Likely cause: Loose heat shield or exhaust
A rattle from underneath is often a loose heat shield on the exhaust. It's annoying but usually not dangerous. Still worth getting checked.
Squealing when starting the engine
Likely cause: Worn serpentine belt
The serpentine belt powers things like your AC and power steering. A squeal means it's getting worn or loose. Replace it before it breaks!
Whining that gets louder with speed
Likely cause: Wheel bearing issue
Wheel bearings help your wheels spin smoothly. If they're worn, you'll hear a humming or whining that changes with speed. Get it checked soon.
Quick Visual Checks
You can spot many problems just by looking! Do a quick walk-around check regularly.
Check for Fluid Leaks
Look under your car for puddles or spots. Different colors mean different fluids: brown = oil, green/orange = coolant, red = transmission fluid, clear = water (usually normal from AC).
Inspect Your Tires
Look for uneven wear, bulges, or cracks on the sidewall. Try the penny test: put a penny head-first into the tread. If you can see Lincoln's whole head, the tires need replacing.
Check Your Wipers
Run your windshield wipers and see if they streak, skip, or squeak. Worn wipers can make it hard to see in the rain. They're easy and cheap to replace!
Look at Your Exhaust
White smoke when starting on cold days is normal. But thick white, blue, or black smoke while driving means something is wrong. Blue smoke = burning oil. Black smoke = too much fuel.
Inspect Belts & Hoses
With the engine off, look at the rubber belts and hoses under the hood. They should be smooth and firm, not cracked, frayed, or mushy. Replace any that look worn.
Check Your Lights
Walk around your car and check that all lights work: headlights, tail lights, brake lights, turn signals, and reverse lights. Ask a friend to help check brake lights!
Important Safety Reminder
If you ever feel unsure about a car problem, always ask a trusted adult or professional mechanic. It's better to ask for help than to guess! Your safety is the most important thing.