There are few feelings worse than turning the key and getting nothing, or worse — a clicking sound that confirms your fears. Here are the eight most common reasons a car won’t start, and how to tell which one you’re dealing with.
1. Flat or Faulty Battery
Symptoms: Slow cranking, clicking sound, or complete silence when you turn the key. Lights may be dim or off.
The most common cause by far. Try jump starting. If the car starts with jump leads but won’t start on its own again after, the battery needs replacement.
2. Faulty Starter Motor
Symptoms: A single loud click when you turn the key, but the engine doesn’t crank. Lights work normally.
The starter motor is the device that physically turns the engine over. When it fails, you’ll often hear a single clunk. This requires a garage visit.
3. Faulty Alternator
Symptoms: The car starts but then dies, or warning lights appear while running. The battery may appear to be charged but the car still won’t start reliably.
The alternator charges the battery while the engine runs. If it fails, the battery drains and the car can’t restart.
4. No Fuel
Symptoms: Engine cranks normally but doesn’t fire. Fuel gauge shows empty or near empty.
It sounds obvious, but fuel gauges can be inaccurate. If the engine is cranking healthily but not starting, and you’re near empty, try adding fuel.
5. Flooded Engine
Symptoms: Engine cranks, strong petrol smell, car may fire briefly then cut out.
More common in older carburetted engines but still occurs in modern vehicles, particularly with repeated short start attempts. Leave the car for 15–20 minutes with the accelerator pressed to the floor, then try starting again without touching the accelerator.
6. Faulty Ignition Switch
Symptoms: Nothing happens when the key is turned, but dash lights come on when you turn to accessory position.
The ignition switch can fail internally. Usually requires a garage diagnosis.
7. Immobiliser Problem
Symptoms: Engine may crank but won’t fire, security light stays on, key fob doesn’t seem to be working.
Modern cars use immobilisers that prevent starting without the correct signal from the key. A damaged key fob battery, a damaged key or a fault in the immobiliser itself can cause this.
8. Fuel Pump Failure
Symptoms: Engine cranks but won’t fire, no issue with battery or electrics. May hear no priming sound from the fuel pump when ignition is turned on (you should hear a brief whirring from the tank).
A failed fuel pump means no fuel reaches the engine. This needs a garage.
When to Call Recovery
If you can’t identify and resolve the cause — or if you can identify it but can’t fix it where you are — call Jam’s on 07369 205 703. We’ll get you to a garage that can diagnose and repair the fault properly.
*Jam’s Breakdown & Recovery covers Milton Keynes, Northampton, Bedford, Luton and surrounding areas. Call 07369 205 703 for 24/7 roadside assistance.*
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