43 answers · 202 cited sources · free, no sign-up
What’s wrong with my car?
Ask it the way you’d ask a mechanic friend. Get a straight answer first, whether it’s safe to drive, and the sources behind it.
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Warning light finder
Tap the light on your dash. See what it means and whether you can keep driving.
Open toolTrouble code lookup
Type a code like P0420 or U0100. We break down what every character means.
Open toolCan I keep driving?
Pick what your car is doing. Get stop now, get it checked soon, or not urgent.
Open toolTire size calculator
Decode a size like 225/65R17 and compare two sizes, speedometer error included.
Open toolThe first thing you want to know
Is it safe to keep driving?
Every symptom page is rated so you know where you stand before you read another word. Each rating follows what that page’s sources say about the problem.
Check my symptomAct now
Pull over or head straight to a shop: flashing check engine light, overheating, spongy brakes, battery light while driving.
Get it checked soon
ABS light, grinding brakes, a coolant smell, a solid check engine light.
Not urgent
A “check fuel cap” light and small EVAP leak codes.
Browse by topic
All topicsCheck Engine Light
9 answers
What the light means, what the codes mean, and when to stop driving.
Recalls
1 answer
How to find open safety recalls on your car and get them fixed for free.
Maintenance
10 answers
How often to do the routine stuff, and what actually matters.
Brakes
9 answers
Noises, shaking, brake fluid and when brakes need a pro right away.
Battery & Starting
5 answers
Clicking, no-starts, dead batteries and how to tell the battery from the starter or alternator.
Cooling & Overheating
6 answers
Temperature gauge running hot, steam, coolant leaks and when to stop driving.
Tires
3 answers
Warning lights, pressure, tread and when a tire needs replacing.
Every answer
All 43 answers on one page, grouped by topic.
Recently answered
- Maintenance
Is it bad to let my car sit all winter? How do I keep the battery and tires from going bad?
Letting a car sit is fine if you prepare it; the usual casualties are a dead battery (Consumer Reports says even a week or two parked can drain one), flat-spotted tires, and mice in the engine bay. Either drive it at least 20 minutes every week or two, or store it properly: hook up a smart battery maintainer, fill the tank, change the oil if it's due, set the tire pressure, skip the parking brake, and block the openings rodents use.
- Maintenance
How often should I wash my car in winter to get the road salt off?
Wash it about every two weeks during salt season, and sooner after driving on heavily salted roads; that's the AAA and NAPA rule, while Consumer Reports sets the floor at once a month. The part that matters most is the underside, so pick a wash with an underbody spray: salt sits on brake lines, suspension and the frame, where AAA says the damage is easy to miss.
- Maintenance
My car door or lock is frozen shut. How do I open it without breaking anything?
For a door that's frozen to its seal, push firmly into the door a few times to crack the ice, then pull; try the other doors and the hatch too. For a frozen key lock, spray lock de-icer into it, or coat the key in alcohol hand sanitizer and ease it in, wait 30 seconds and turn; never force the key or pour hot water into the lock.
- Maintenance
What washer fluid should I use in winter, and what do I do if it freezes?
Use a winter-blend washer fluid whose label rating is colder than the coldest temperature you drive in (many are rated around -20°F; some go to -50°F), and run the old summer fluid out before you fill up, because summer fluid is mostly water and dilutes the winter blend. If it has already frozen, don't keep pressing the washer button: let it thaw in a warm garage or as the engine warms up, then refill with full-strength winter fluid.
- Maintenance
How do I defrost a frozen windshield fast, and is hot water safe?
Start the engine, set the heater to defrost with the temperature on full heat, and once the ice starts to soften, clear it with a plastic scraper; a de-icer spray (store-bought, or rubbing alcohol mixed with water) speeds it up when the ice is thick. Don't pour hot or even warm water on the glass: AAA says the sudden temperature change can crack the windshield.
- Maintenance
How do I drive on ice, and what do I do if my car starts to skid?
Slow down well below the limit, leave far more room than usual, keep cruise control off, and do one thing at a time, smoothly, braking early and gently. If the car starts to skid, take your foot off the gas, don't slam the brakes, look where you want to go and steer there with small, smooth corrections; if you must brake hard and have ABS, press firmly and hold it even when the pedal pulses.
How we write every answer
Answer first
The direct answer is in the first two sentences. Detail comes after, for anyone who wants it.
Sourced, not guessed
Owner’s manuals, government agencies, AAA and established repair sources, listed on every page.
Safety called out
If a problem can hurt you or wreck an expensive part, the page says so up top.