Car Won't Start? Get Instant AI Diagnosis

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Quick Answer: Why Car Won't Start?

When a car won't start, the most common cause is a dead battery (45% of cases), followed by starter motor failure (20%), alternator problems (15%), or empty fuel tank (10%). Listen for clicking sounds (battery), no sound (starter), or engine cranking without starting (fuel/ignition).

Common Causes & Solutions

Dead Battery

45%

Most common cause. Battery loses charge over time or due to lights left on. Listen for clicking sounds when turning the key.

Cost: £50-200Low Priority

Bad Starter Motor

20%

Starter motor fails to engage. You may hear nothing when turning the key, even with working lights and radio.

Cost: £300-600Medium Priority

Faulty Alternator

15%

Alternator fails to charge battery while driving. Car may start with jump but dies when cables removed.

Cost: £400-800High Priority

Empty Fuel Tank

10%

Simple but common. Engine cranks but won't catch. Always check fuel gauge first before assuming worse.

Cost: £30-60Low Priority

Bad Ignition Switch

5%

Key won't turn or no electrical response when turned. May affect other electrical systems too.

Cost: £125-275Medium Priority

Other Issues

5%

Includes corroded terminals, blown fuses, security system lockout, or bad fuel pump.

Cost: VariesMedium Priority

Quick Diagnosis: What Do You Hear?

🔊

Clicking Sound

Rapid clicking when turning the key

Likely Cause: Dead Battery

  • Try jump-starting
  • Check battery age (3-5 years typical)
  • Clean battery terminals
🔇

No Sound At All

Complete silence when turning the key

Likely Cause: Starter Motor

  • Check if lights work
  • Try tapping starter (temporary fix)
  • Professional replacement needed
🔄

Engine Cranks But Won't Start

Engine turns over but doesn't catch

Likely Cause: Fuel or Ignition

  • Check fuel gauge
  • Listen for fuel pump (buzzing sound)
  • May need spark plugs or fuel pump

Grinding or Whirring

Grinding noise when starting

Likely Cause: Starter Gear

  • Stop trying immediately
  • Starter not engaging flywheel
  • Requires starter replacement

🚨 Emergency Tips When Your Car Won't Start

🔋Battery Quick Fixes

  • Clean corroded terminals with baking soda
  • Tighten loose battery connections
  • Try the "key dance" - turn key on/off 10 times
  • Rock automatic cars in neutral (parking brake on)

⚙️Starter Workarounds

  • Tap starter with tool while someone turns key
  • Shift between Park and Neutral repeatedly
  • Turn steering wheel while starting
  • Try starting in Neutral instead of Park

DIY Diagnosis Steps

1

Check Your Dashboard

Turn the key to the "ON" position (not start). Do the dashboard lights come on? If not, your battery is likely dead. Dim lights indicate a weak battery.

2

Test the Battery

Try turning on the headlights. Bright lights with no start = starter issue. Dim or no lights = battery issue. A battery can have enough power for lights but not enough to start.

3

Listen Carefully

Turn the key and listen. Clicking = weak battery. Nothing = starter or ignition. Cranking = fuel or spark issue. Have someone else turn the key while you listen near the engine.

4

Check Simple Things

Ensure car is in Park/Neutral, check fuel gauge, make sure steering wheel isn't locked, verify key fob battery. These simple issues cause 15% of no-start problems!

5

Try Jump-Starting

If battery seems weak, try jump-starting. If it starts but dies when cables are removed, the alternator is bad. Let the car run for 20 minutes after jump-starting to recharge.

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Frequently Asked Questions

What are the most common reasons a car won't start?

The most common causes include a dead battery (45% of cases), bad starter motor (20%), faulty alternator (15%), empty fuel tank (10%), or bad ignition switch (5%). Other causes include corroded battery terminals, blown fuses, or security system issues.

How do I know if it's the battery or starter?

If you hear clicking sounds when turning the key, it's likely the battery. If the lights and radio work but the engine doesn't turn over at all, it's probably the starter. No lights or electrical functions usually means a completely dead battery.

Can I jump-start my car if it won't start?

Yes, if the battery is the issue. However, jump-starting won't help with starter, alternator, or fuel problems. If the car starts but dies immediately after removing jumper cables, the alternator is likely failing.

How much does it cost to fix a car that won't start?

Costs vary by cause: Battery replacement £50-200, starter motor £300-600, alternator £400-800, ignition switch £125-275. Always get a proper diagnosis first to avoid replacing the wrong part.