What is your car doing?

Pick the problem that sounds like yours. Each guide explains the most likely causes and the cheapest things to check first. If you already have a check engine code, use the OBD2 code lookup instead. Know your vehicle? See common problems by vehicle.

• Car Won't Start: What to Check Based on What You Hear

  A car that won't start usually tells you why by what it does: nothing, clicking, or cranking without firing. Match your symptom and see what to check first.

• Car Cranks But Won't Start: Fuel, Spark or Air?

  Your engine turns over but never fires. Work through fuel, spark and air in a sensible order, and learn the signs of each failure before you spend money.

• Clicking Noise When Starting: Battery, Starter or Engine?

  Clicking when you turn the key usually means a weak battery or a failing starter, but a tick after the engine starts is a different problem. Here is how to tell.

• Rough Idle: Why Your Engine Shakes or Stumbles at a Stop

  A rough idle can come from spark, air leaks, dirty parts or engine mounts. Match when it happens (cold, warm, A/C on) to find the likely cause.

• Car Stalls While Driving: Causes and What to Do

  A car that stalls while driving is a safety risk. Learn what to do right now, and how stalling at stops, under load or when hot points to different causes.

• Check Engine Light Flashing: What It Means and What to Do

  A flashing check engine light usually means an active misfire that can damage the catalytic converter. Learn what to do right now and how to find the cause.

• Car Overheating: What to Do Right Now and What Causes It

  If your car is overheating, act now to avoid engine damage. Safe steps to take on the road, and the common causes from low coolant to a failed fan.

• Transmission Slipping: Signs, Causes and What to Check

  Engine revs climbing without the car speeding up is a classic slipping transmission. Learn the common causes and the cheap checks to do first.

• Brakes Squeaking: Normal Noise or Time for New Pads?

  Squeaking brakes can be harmless or a warning that pads are worn out. Learn which noises are normal and which mean stop driving and get them inspected.

• Car Using or Burning Oil: Causes and What to Check

  If your engine keeps needing oil, it is either burning it or leaking it. Learn the signs of each, the cheap checks to do first, and when to stop driving.

• Losing Coolant but No Visible Leak: What to Check

  Coolant that keeps disappearing without a puddle can be a small leak or a serious internal problem. Learn the warning signs and what to check first.

• A/C Blowing Warm Air: Causes and What to Check First

  When your car's air conditioning stops cooling, the cause is often low refrigerant, a compressor that is not turning on, or a fan problem. Here is how to tell.

• Steering Wheel Shaking: Causes by When It Happens

  A shaking steering wheel can mean an out-of-balance tire or something more serious like worn steering parts. Match when it shakes to find the likely cause.

• Exhaust Smell Inside the Car: What to Do and What It Means

  An exhaust smell inside your car can mean a leak that lets carbon monoxide in. Learn what to do right away and how to find the source.

• Engine Ticking Noise: What Causes It and When to Worry

  An engine tick can be harmless or an early warning of low oil or a worn valvetrain part. Match when it happens to find the likely cause and what to check first.