My car won’t start, what should I do?

Your car won’t start, but why? And what should you do? Here are some possible reasons your car might not start – as well as the solutions.

Written by

Rory Reid

Car and technology expert

Last Updated

21 OCTOBER 2022

5 min read

1. A flat or faulty battery

If your car won’t start, there are a number of possible causes. But the most likely one is that your battery is flat or faulty. When you try to start the engine, do you hear your engine slowly turning but failing to start, a faint click or complete silence? If so, a flat battery might be the issue. 

It’s fairly common to find that your car won’t start if you haven’t used it for a while – for example, over the Christmas holidays. Your battery could also go flat if you accidentally leave your lights on overnight. 

To get your car going again, you may need to jumpstart the engine. You can do this with some jump leads and another car with a fully charged battery – but only if you know what you’re doing. You don’t want to injure yourself or damage one of the cars. 

If the battery has charge but still fails to start your car, it could be that you need to tighten or safely clean the connections, or get help from a mechanic. It also might be that your battery is getting old – most need to be replaced after about six years.

2. A faulty starter motor 

If you hear a loud clicking noise when you try to start your car, it could mean there’s something wrong with the battery. But it could also suggest a problem with the starter motor. This is the electrical motor connected to the battery. It sets the engine in motion when you turn on the ignition.

The most likely issue is a poor wiring connection or faulty solenoids (electromagnets). A faulty starter motor is difficult to fix yourself, so you may need to get help bump starting your car if it’s a manual. This is done by asking someone to push your car whilst you’re inside it with the ignition in the ‘on’ position and the clutch down, then ‘popping’ the clutch back up once you’re moving.

You may want to phone a friend or a recovery service to tow you to a garage.

3. Fuel problems

When it’s cold outside, your car needs more fuel to get going. If you’re already running low, the engine could have trouble starting. A simple top-up should solve the problem.

If your fuel filter is clogged, the petrol or diesel won’t reach the engine, making it difficult to burn the fuel needed to start. Manufacturers generally recommend replacing the fuel filters every two years, or 15,000-20,000 miles, but check your handbook for guidance.

4. A flooded engine

If your car won’t restart or starts briefly but keeps cutting out, your engine may have flooded. This can happen with older petrol cars when there’s too much fuel and not enough air in the engine, preventing the spark plugs working. 

The trick is to be patient. Wait a few minutes, then with the gearbox in neutral and the handbrake on. Then put your foot flat on the accelerator and start the engine. Once it catches, leave it to idle for a few seconds so it warms up properly before you set off. If this doesn’t work, you may need to call the professionals.

5. A faulty key fob

Some modern cars come with keyless entry and ignition where the car starts at the push of a button. The button receives a coded signal from the smart key fob to work, so if the engine fails to recognise your key, it won’t start.

If this happens to you, you may simply need to replace the key fob battery. You’ll know this is the case if the central locking system doesn’t work, either. Sometimes you can start your car with a dead key fob by holding it against the start button when you press it.

If you think the key fob itself is faulty, contact your dealer for help.

Top tip

If your car won't start because you can’t turn the key, the steering wheel may have locked. Try slowly pulling the steering wheel left and right, while carefully turning the key in the ignition.

6. Cold weather

If it’s particularly chilly outside or your car’s spent time in the snow, you may have a frozen fuel line. This is when water collects in the fuel line and is more common when your tank is on the empty side. 

To stop this happening, mechanics recommend keeping your tank at least half full during the winter months. If your fuel line isn’t the problem, you may have damp spark plugs. If you’re not sure, it’s best to call a mechanic – and your insurance could help with this.

The benefits of breakdown cover

Regardless of what caused your breakdown, you’re likely to need help. This is when breakdown cover comes into its own.

Comparethemarket is here to help you find car insurance and breakdown cover at a price that’s right for you. Start a quote today to see if you could save on your car insurance.

Frequently asked questions

What’s the most common cause of vehicle breakdown?

The number one reason cars break down is a flat battery. There are lots of possible reasons this might happen, but the main one is human error – namely, you left the lights or radio on or you’ve left the car sat for months without trying to start it.

Can I call out assistance if I don’t have breakdown cover?

If your car won’t start and you don’t have breakdown insurance in place, you can still call for roadside assistance. However, you may find yourself landed with a pretty hefty bill. By having the right insurance in place, you can rest assured, knowing you’re covered.

What tools should I carry in my car in case I break down?

It’s helpful to keep a few pieces of kit in your boot, so if you find your car won’t start, you’re prepared. In case of emergencies, we recommend having jump leads, a tyre jack, a spare tyre and an empty fuel can on hand.