1. Starter: The starter motor may be faulty. Try tapping the starter motor with a hammer or metal object while someone tries to start the engine. If the engine starts, the starter motor may need to be replaced.
2. Ignition switch: The ignition switch may be faulty and not providing power to the starter motor. Try turning the key to the "ON" position and see if the starter motor engages. If it does not, the ignition switch may need to be replaced.
3. Timing belt/chain: The timing belt or chain may have snapped or jumped, preventing the engine from turning over. Inspect the timing belt/chain to see if it is broken or damaged. If it is, it will need to be replaced.
4. Fuel system: There may be a problem with the fuel system, such as a blocked fuel filter or a faulty fuel pump, which is preventing fuel from reaching the engine. Check the fuel filter and fuel pump to ensure they are working correctly.
5. Engine immobilizer: If your car has an engine immobilizer, it may be preventing the engine from starting. Try disabling the immobilizer and see if the engine starts.
