Engine cranks but won't start — possible causes
If the starter turns the engine at normal speed, the battery and starter are probably fine. The problem is usually in the fuel supply, ignition or one of the engine management sensors.
Possible causes
- Fuel pump or fuel filter problem
- Faulty spark plugs or ignition coils (petrol engines)
- Glow plug problem in cold weather (diesels)
- Crankshaft or camshaft sensor fault
- Immobiliser blocking fuel delivery
What you can safely check yourself
- Whether you hear the fuel pump hum briefly when the ignition is switched on
- Whether the immobiliser or Check Engine light is flashing
- Whether the problem started after refuelling or a hard frost
When to call a mechanic
If the car doesn't start after 2–3 attempts, stop cranking. Prolonged cranking can flood the engine, drain the battery and overheat the starter.
How MobilaisServiss can help
We read fault codes and live sensor data on site with computer diagnostics to find the cause, and agree the repair before any work starts.
This is a general guide, not a diagnosis. The exact cause can only be confirmed after inspecting the car.