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If your car won’t start, it could be a simple problem or something more serious. In 2025, new technologies and advanced batteries bring new challenges. Find out the most common causes and what to do!
Imagine the following situation: you are about to leave for an important appointment, you turn the key in the ignition and the car won’t start. Frustrating, isn’t it? Before calling a mechanic or a tow truck, it is essential to understand the main reasons why a car might not start.
This article explores the most common causes of this problem and offers practical solutions to resolve it.
Battery discharged
The battery is one of the main components responsible for starting the car. If it is discharged, the vehicle will not have enough power to activate the starter motor.
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Signs of a dead battery:
- Weak or flickering headlights;
- Clicking noise when turning the key;
- Instrument panel blank or unstable.
If the problem is the battery, an immediate option is to recharge it using jumper cables connected to another vehicle. If the battery is old or has recurring failures, it may need to be replaced.
Additionally, the lifespan of a battery typically ranges from three to five years. If your car is taking longer to start, even after charging, it could be an indication that the battery is nearing its end.
Some batteries have charge indicators that are easy to read. Avoid draining the charge by leaving lights or a radio on. linked unnecessarily.
Fuel system problems
If there is fuel in the tank but the car won't start, there may be faults in essential components of the fuel system.
Main causes:
- Clogged fuel filter: prevents fuel from reaching the engine.
- Faulty fuel pump: fuel is not sent to the cylinders.
- Air flow sensor failure: The engine is not receiving the correct amount of fuel.
A simple way to check the fuel pump is to turn the key to the “on” position and listen for a slight humming sound coming from the tank. If there is no sound, the pump may be faulty.
Keeping the fuel filter clean and replacing it within the manufacturer's recommended period can prevent clogging and ensure proper system operation. In addition, using quality fuel reduces residue formation and prevents damage to the fuel pump.
Defective starter motor
The starter motor is responsible for turning the vehicle's engine when it starts. If it is faulty, the car will not start, even if the battery is charged.
Signs of starter motor failure:
- Single click when turning the key, without the sound of the engine turning;
- Dashboard lights come on, but the engine shows no sign of life;
- Burning smell coming from the engine compartment.
If there are signs of overheating, such as a burning smell or smoke, avoid trying to start the car repeatedly, as this could further damage the starter motor. Some faults can be resolved by simply cleaning the electrical contacts of the starter motor, but in more serious cases, replacement will be necessary.
Faulty ignition switch
The ignition switch is responsible for sending power from the battery to the car's electrical system. If it is faulty, the engine may not receive the current it needs to start.
How to identify the problem:
- The car does not respond when turning the key;
- The engine suddenly turns off while the car is moving;
- The instrument panel does not light up.
If the ignition switch is suspected of being faulty, it should be replaced by a qualified professional. In some cases, a simple adjustment to the ignition cylinder may solve the problem, but it is important to ensure that the electrical system is working properly.
Worn spark plugs
Spark plugs are responsible for generating the spark needed to burn fuel and start the engine. If they are worn or dirty, the car may not start or may malfunction.
Signs of worn spark plugs:
- Engine misfiring or sputtering;
- Increased fuel consumption;
- Difficulty starting.
Worn spark plugs can also reduce the car's power and cause engine surges. Periodic replacement of spark plugs, as per the vehicle's manual, is essential to avoid problems.
Steering lock problems
The steering lock is a safety mechanism that prevents the car from being started without the correct key. If it is locked, the key may not turn in the ignition.
How to unlock:
- Turn the steering wheel gently to both sides while trying to turn the key;
- Use a specific lubricant for ignition locks;
- Avoid forcing the key as this may damage the ignition cylinder.
If the lock persists, a qualified locksmith may be required to resolve the issue. One preventive tip is to avoid turning the steering wheel too hard when turning off the car, as this may trigger the lock unintentionally.
Common problems in modern vehicles
Newer cars have advanced electronic systems that can prevent the engine from starting.
Main causes:
- Remote control battery dead: Some vehicles will not start if the key fob battery is low.
- Presence sensor failure: If the car has a keyless start system, check that the key fob is inside the vehicle and working properly.
- AdBlue Requirements: Modern diesel vehicles using AdBlue may not start if the fluid level is low.
Furthermore, failures in the car's electronic modules can compromise starting. Keeping the software up to date and carrying out periodic checks can prevent unexpected problems.
Cold weather and difficulties in departure
The cold can affect the car's performance in several ways.
Effects of cold on the car:
- Low battery: cold weather reduces battery capacity;
- Thick engine oil: makes lubrication and engine operation difficult;
- Frozen fuel: at very low temperatures, gasoline or diesel may have difficulty burning.
In addition to the basic measures, using a thermal blanket over the engine or keeping the car in a closed garage can help minimize the effects of the cold.
There are many reasons why a car won't start, from simple problems like a dead battery to more complex faults in the fuel system or ignition. Keeping up with preventive maintenance and being aware of the signs of your vehicle's malfunction can help you avoid unnecessary problems and costs.
If the problem persists, the best option is to seek out a trusted mechanic for an accurate diagnosis and to carry out the necessary repairs. After all, a well-maintained car is synonymous with safety and peace of mind in everyday life.
