Car won’t start – what should I do?

It can be frustrating when your car won’t start, especially when it's cold and dark. Common causes include flat batteries and fuel issues. This article explains why cars fail to start and offers tips to diagnose and fix these problems, helping you get back on the road quickly.

It always seems to happen at the most inconvenient times but whilst its easier said than done you should always try stay calm. Depending on why your vehicle won’t start, you may be able to resolve the issue yourself. If not, you should call roadside assistance or breakdown services .
It’s worth purchasing breakdown cover in case you find yourself unable to start your vehicle whilst out on the roads.

There are various reasons why your start won’t start with varying levels of severity. Here are some of the more common reasons:

A flat or faulty battery is the most common reason your car won’t start, especially in winter when cold temperatures make it harder for the battery to hold charge. Common causes of a flat battery include:
- The vehicle hasn’t been driven in a significant amount of time - A fault with the battery components - Something electrical being left on for example lights A clicking noise when you turn the key is often a sign that a battery issue is preventing your car from starting. If this is the case, you can try jump starting the vehicle, however, the battery may need replacing. A vehicles battery should be replaced every three to five years on average. To reduce the risk of a flat battery during cold weather, try driving your car more frequently and switch off any unnecessary electricals.

A common reason your car may not start is simply running out of fuel. If this happens, top up your tank. Misfuelling can also prevent starting; in this case, the fuel system must be drained so you'll need to contact roadside assistance.
A blocked fuel filter may also stop the engine from getting fuel, so it’s recommended that the filter should be replaced every two years or 15,000-20,000 miles. In cold weather, keep your tank at least half full to prevent fuel line freezing.

If you can’t turn the key in the ignition, your steering lock might be jammed. This often happens when a wheel is pressing hard against a kerb or when the car is parked with the steering wheel in full lock. You can usually free a jammed lock without calling for assistance, by trying the following:
- Turn the steering wheel from side to side whilst simultaneously turning the key back and forth - Press the brake pedal and release the handbrake, letting the car roll slightly. Then, reapply the handbrake and attempt to turn the steering wheel once again.

A problem with the starter motor may stop your vehicle from starting. The starter motor is the electrical motor connected to the battery and sets the engine in motion when you turn the key or press the start button.
A simple way to check for starter motor issues is to see if the lights come on when you turn the key. If the lights come on but the engine fails to start, it’s likely that the starter motor is at fault. Additionally, if your battery is fully charged but you hear a clicking sound when trying to start the engine, this usually indicates a faulty starter.

Sometimes, your cars security system might stop the engine from starting if the immobiliser doesn’t recognise your key. This may be because the battery in your key fob is low. First, you should try replacing the battery or try the spare key.
If this doesn’t work, hold the fob against the start button while pressing it, or hold the fob near to the ignition switch whilst you turn the key. If none of the above work, you should contact your local dealer as the key may need to be reprogrammed or replaced.

A flooded engine occurs when there’s excess fuel and insufficient air reaching the combustion chamber. This often happens with cold engines when you move your vehicle just a short distance, switch the engine off, then try to start it again.
After you switch off the engine, any unburned fuel left inside can wet the spark plugs, making it hard to restart. If your engine is flooded, you’ll likely hear a ‘whirring’ sound when you turn the key, and you may also notice a strong smell of fuel. It you suspect your engine is flooded, wait for a few minutes with the gearbox in neutral and the handbrake on. Then, press the accelerator pedal to the floor while you try and start the engine for a few seconds. Avoid cranking for longer, as this could drain the battery or damaging the starter motor. Once the engine starts, let it idle for a few minutes to warm up properly before driving.

If you have run out of AdBlue, your engine won’t restart. You may need to call out a mechanic to restart the vehicle.
Your vehicle will usually show a warming with a countdown on the dashboard; this will help it to avoid running out.

Alternator problems include issues with the alternator drive belt and wiring. The alternator recharges the battery and supplies power to your cars electrical systems while running. Failures may occur due to damaged wiring or a worn drive belt. If there’s no spark from the ignition coil, this could indicate a wiring problem.
A failing alternator cannot recharge the battery effectively, which can result in reoccurring starting issues. Signs of a failing alternator include dimming headlights, warning lights and faulty electrical accessories.

You’ll need to use a pair of jump leads to connect your battery to a second vehicle with a fully charged battery. However, we always recommend calling an expert first.

Remain with your vehicle and call for breakdown assistance. If possible, try jump starting your car battery or check for obvious issues like a loose fuel cap.

No, you should not jump-start a hybrid or electric vehicle. Refer to your vehicles manual or contact your breakdown service for guidance.

A battery can recharge whilst driving however you should drive for at least 30 minutes after a jump start to ensure it recharges sufficiently. Ideally choose a route with minimal traffic and avoid using electrical systems that consumer a lot of power.
Now that you’re better informed about what to do if your car won’t start, why not consider broadening your road safety knowledge by exploring our other articles.