DIY: Easy
Car Won't Start: What to Check Based on What You Hear
What happens when you turn the key narrows it down fast. Silence points to power. Clicking points to the battery or starter. A normal crank that never catches points to fuel, spark or air. Find the case that matches yours below.
Stay safe first
- If you smell gasoline, stop cranking. Raw fuel and repeated cranking is a fire risk.
- Crank in short bursts and let the starter rest between tries. Long continuous cranking can overheat it.
Nothing happens: no click, no crank, dash lights dim or dead
Likely causes
- Dead or very weak battery
- Loose or corroded battery terminals
- Blown main fuse or a bad ground strap
What to check
- Turn the headlights on. If they are dim or dead, the battery or its connections are the problem.
- Look at the battery terminals for white or green crust and wiggle each cable. A loose cable can look exactly like a dead battery.
- Try a jump start. If it starts, have the battery and charging system tested, since a bad alternator will drain a new battery too.
Fast clicking, or one loud click, and the lights dim
Likely causes
- Weak battery that cannot turn the starter
- Poor connection at the battery or the starter
- Failing starter motor or starter solenoid
What to check
- Fast clicking almost always means a weak battery. Try a jump start first.
- If a jump gives the same click, check the cable ends at both the battery and the starter.
- A single loud click with strong lights points toward the starter itself.
The engine cranks normally but never fires
Likely causes
- No fuel reaching the engine (empty tank, fuel pump, relay or fuse)
- No spark (crankshaft position sensor, ignition coils)
- Anti-theft system blocking the start
What to check
- Check the fuel gauge honestly. A gauge that is wrong is more common than you would think.
- Turn the key to ON without cranking and listen near the rear seat for a short hum from the fuel pump.
- Open the "Car Cranks But Won't Start" guide under Related guides below for the full checklist.
It starts for a second, then dies
Likely causes
- Anti-theft (immobilizer) system rejecting the key
- Fuel delivery problem
- Dirty throttle body or a vacuum leak
What to check
- Watch the security or key-shaped light on the dash. If it blinks while you crank, try your spare key.
- If the engine runs only while you hold the gas pedal, suspect the idle air control or a vacuum leak.
Narrow it down for your vehicle
The same symptom can have different likely causes depending on your year, make, model and engine. Describe what you are seeing and CaliperAI will help narrow down the likely causes for your vehicle.
Related guides
General information about this symptom, not a diagnosis of your specific vehicle. Safety-critical work such as brakes, fuel and airbags is best left to a qualified mechanic.