When you are heading out in your car it can be frustrating to find it won’t start. Whether you are in a hurry or popping out hearing the engine turn over but going nowhere can be more than irritating.
Whether it is fuel issues or a flat battery caused by the chilly weather, there are several reasons this might happen, with some easier to fix than others. To help drivers get back on the road, The AA has shared the top 11 reasons your car might not start and what to do about it.
Shaun Jones, Patrol of the Year at The AA says: “Diagnosing starting problems involves recognising symptoms. If you don’t hear any noise when starting the car, it could mean there’s a battery connection issue, while rapid clicking suggests electrical problems like a flat battery or alternator fault.
“A single click usually points to starter or relay issues. If the engine cranks but won’t start, it might be due to a flooded engine, empty tank, or fuel system fault. An engine starting but cutting out could indicate fuel injection or immobiliser issues.
“In some cases, you may be able to fix the issue yourself and get back on the road. For example, jump-starting a flat battery is fairly straightforward and can often resolve the problem, though it’s wise to seek expert advice if it doesn’t work.
“However, more complex issues will typically call for assistance. Signs of a blown starter fuse, such as no engine response, smoke, or visible damage to the fuse box, should always be looked at by a trained mechanic.” Here are the 11 most common reasons your car won’t start.
Flat or faulty battery
A flat or faulty 12-volt battery is the most common reason cars won’t start, often caused by leaving lights or electrical components on or not driving the car for a while. Cold weather can also make battery issues worse. If you hear rapid clicking when turning the key, the battery is likely to blame. Try jump-starting it, but if the problem persists, you may need a new battery or a mechanic to check the electrical system.
Starter motor problems
The starter motor is responsible for turning the engine over when you start your car. If this component fails, your car won’t start. A common sign of a faulty starter motor is a loud click when you turn the key. If you hear this, it’s a sign that the motor isn’t engaging with the battery properly. To resolve this issue, a mechanic will need to inspect the starter motor and the car’s electrical system
Fuel problems
Fuel-related issues can also prevent your car from starting. This can include a malfunctioning fuel pump or problems within the fuel system. In some cases, putting the wrong type of fuel in your car can cause starting issues. If your car sputters, hesitates, or doesn’t start at all, fuel issues could be to blame. If you suspect the wrong fuel was added, AA Fuel Assist can help you resolve the problem.
Electrical or wiring problems
Electrical problems are another common cause of non-starting cars. This can involve issues with the fuse box, battery cables, or even the body control unit. Sometimes rodents can cause damage by gnawing on the wiring if the car hasn’t been driven for a while.
Engine problems
Problems with the engine’s internal components can also prevent a car from starting. Issues such as a faulty crankshaft, timing belt, or timing chain are often the culprits. If the engine turns over more quickly than usual, it’s a sign that there could be mechanical issues. In these cases, the engine will need professional attention to repair the damaged parts and get your car running again.
Faulty immobilisers
Many modern cars are equipped with security systems that use an immobiliser to prevent theft. If the immobiliser doesn’t recognise your key, it may prevent the car from starting.
This could happen if the battery in your key fob is low or if the system malfunctions. Look for a flashing key symbol or warning lights on the dashboard. If this happens, try using a spare key or hold your key fob close to the start button. If that doesn’t work, you may need to replace the key or reset the system AA Key Assist could also support you with this.
Alternator problems
The alternator is responsible for generating electricity to power your car’s electrical systems and charge the battery. If the alternator is faulty, it could prevent your car from starting or cause electrical components to fail while driving.
Common problems include issues with the alternator drive belt or wiring. If you notice electrical malfunctions, such as dim lights or a malfunctioning radio, the alternator could be the issue and should be checked by a mechanic.
Engine intake problems
Problems with the engine intake system, including faulty fuel injectors, throttle bodies, and sensors, can cause starting issues. If you notice your car struggling to start and hear whining or sputtering sounds, the issue may lie with the fuel system. A mechanic will need to inspect the intake system and replace any damaged parts to get your engine running smoothly again.
Jammed ignition or steering lock
If you can’t turn the key in the ignition, it could be due to a jammed steering lock. This often happens when the steering wheel is pressed hard against a curb or parked in full lock. To fix this, gently rock the steering wheel while trying to turn the key. If that doesn’t work, seek assistance from a professional to free the lock without damaging the ignition.
Spark plug issues
Spark plug issues are a common cause of starting problems in petrol engines. A flooded engine, often caused by turning off the engine too soon after a cold start, can cause unburned fuel to wet the spark plugs, making it hard to restart the car. If you hear a fast cranking sound or notice a strong petrol smell, your engine may be flooded. In such cases, it’s best to let the engine dry out, or call a mechanic to check and replace the spark plugs if necessary.
Low Ad Blue
If your car runs on diesel and you’ve run out of AdBlue, the car won’t start. AdBlue is used in some diesel engines to reduce emissions, and when it runs out, the engine can’t restart until it’s topped up. Some car models require software intervention to reset the system once AdBlue is added. Always keep an eye on your AdBlue levels, as the car will give you a warning before it runs out.