It can be frustrating and stressful if you get in your car and it won’t start, particularly if you’re out and about. There are various reasons why your car might be struggling to start and it can be hard to determine which issue you’re dealing with.

Our advice will help you identify what’s causing your car to fail on you and if there’s anything you can do to get your vehicle going again.

Why won’t my car start? How do you diagnose a car that won’t start?

There are a number of different reasons your car won’t start, from being out of fuel, to more complex issues such as electrical problems. But some causes are more common than others and some are easier to identify.

Engine turns over, but doesn’t start

Low fuel level

We don’t want to sound obvious, but if your car doesn’t start it could just be out of fuel. If a fuel tank is nearly empty, even though the engine may have been running fine before you stopped, it could later refuse to start, particularly if you’ve parked on a hill (the slope could cause the fuel to run away from the pick-up pipe inside the tank).


What to do – If your fuel gauge is showing as nearly empty, add some fuel to the tank, but be aware that you may need to try starting your car for some time before the fuel reaches the engine. 


If you think your fuel gauge could be broken, you might need to book your car into a local garage for a vehicle diagnostic – otherwise you could end up being surprised by an empty fuel tank more often than you’d like!

Engine immobiliser

An engine immobiliser is an anti-theft system built into your car’s computer. It stops the engine from starting without using the vehicle’s authorised key. Sometimes, it’s your car’s own security system that stops the engine from starting – if the immobiliser fails to recognise your key, then your engine won’t start at all. On some cars fitted with an immobiliser, the car will appear completely ‘dead’, on others the engine will turn over but not start.


What to do – Try locking and unlocking the car with your key fob, or manually with the key itself, before trying to start the engine again.


If this doesn’t work, we’re here to help you get to the root of the problem. Starting problems can be annoying and stressful, so at Fixter we want to make it as hassle-free as possible for you to get your car fixed. Our experienced mechanics can help diagnose your vehicle’s issues with a car diagnostic. With our seamless, end-to-end service your car will be collected and delivered by our fully-insured drivers and you’ll be kept up-to-date from start to finish.

Flooded engine

If you have a petrol engine, your car may be struggling to start if there’s too much fuel in the engine, also known as a flooded engine. This can sometimes happen if you’ve started the car from cold and then stopped it again almost immediately, however sometimes it can happen for no apparent reason at all! The engine may sound slightly different when you turn the key, perhaps turning over faster than usual.


What to do Most cars have a built-in cure for this – press the accelerator pedal fully to the floor and hold it there. Then turn the key in the ignition for 20 seconds or so. If your car starts, don’t stop again before you’ve driven the car 2-3 miles to make sure that any access fuel is burnt off.

Faulty spark plugs

If your spark plugs are damaged or faulty, your car can fail to start. If this is the issue, when you turn your key your engine may turn over or make a clicking sound, but your car won’t start. If your spark plugs are bad, the fuel is not being lit when you turn the ignition therefore your engine won’t manage to start up.


What to do – If not all the spark plugs are faulty (each cylinder in the engine has its own spark plug), sometimes you may be able to get the car to start by turning the ignition on and off a few times, for 4-5 seconds, before trying to start. If your car still won’t start, you may need to book your car in for a spark plug replacement.


If your spark plugs are old or damaged, replacing them may solve your starting problems. You should get replacement spark plugs fitted as soon as possible. Each car requires a particular type of spark plug made from specific materials and with an exact spark plug gap that is set by a mechanic during installation. Booking a repair with Fixter couldn’t be easier. Simply select the services you need online, choose where and when you’d like us to collect your car, our drivers will take it to one of our vetted, local garages, and we’ll return your car back to you once the work is complete. As easy as that!

Nothing happens when the ignition is turned

Flat or faulty battery

If nothing happens at all when you try to start your car, the most likely explanation is a flat or faulty battery. A flat battery can be caused by a number of things, such as your lights or radio being left on, something in the electrical system causing a battery drain, or even a faulty battery that won’t hold its charge. Often a weak battery will fail as soon as the weather gets colder, as frosty temperatures make it harder for the battery to start the engine.


What to do – Check the battery terminals, making sure they’re secure and free from corrosion. If you make a lot of short journeys, be sure to take your car on a long journey every so often – this will help charge the battery. One way you can test to see if the battery is the problem is by jump starting your car. If the jump start works, you’re most likely dealing with a bad battery or an alternator that’s having trouble recharging the battery. At the first sign of trouble (difficulty starting your car, frequent stalling, dim headlights, dashboard warning lights) have the battery tested or replaced

Faulty starter motor

If your car won’t start, it’s possible that the starter motor itself is failing. The starter motor is an electric motor that turns over or “cranks” the engine to start when you turn the ignition. If you hear a loud clicking noise when you try to start the engine, then this is a tell-tale sign of a faulty starter motor and/or an electrical fault which will require inspection and diagnosis to repair.


What to do – You may be able to ‘bump-start’ or ‘push-start’ your car, but only attempt this if you, or somebody who can help you, have experience of bump-starting. This allows you to start the car by using the rotational movement of the wheels to turn the engine over instead of the battery or starter motor. However, this can be dangerous and could do more damage to the engine, so we recommend booking a vehicle diagnostic or starter motor repair to get you back on the road quickly and safely.

How much does it cost to replace spark plugs?

If your car won’t start it could be due to damaged or failing spark plugs. The cost of replacement spark plugs depends on the make and model of your car. Costs can range from £40 to £350, with the average price in the UK working out at £97.

How much does it cost to replace a car battery?

If your battery is going bad or has corroded terminals, it could lead to your engine stalling whilst driving or not starting. It’s important to get a replacement battery as soon as possible to avoid a frustrating and inconvenient breakdown. The cost of a replacement battery ranges from £100 to £350, with the average cost in the UK being £150.


How much does it cost to fix a starter motor?

Your car might be failing to start due to a faulty starter motor. If this is the case a mechanic will be able to fix it or fit a replacement starter motor. The cost of a new starter motor ranges between £228 to £498, with the average UK replacement price working out at £290.

About Fixter

Fixter is revolutionising the car maintenance industry, one repair at a time. Fixter was founded to make car maintenance as easy as booking a taxi. Digital, transparent and stress-free, with world-class customer service. Since launching in Manchester in 2017, Fixter has expanded to more than 100 towns and cities across the UK and provided thousands of car owners with honest, convenient and affordable car repair services.