What to Do When Your Car Won't Start
Ellie Dyer-Brown, 18 days ago
5 min read
- Car ownership
- Diagnostic
FixMyCar explains what to do if your car won't start and what could be causing it.
When your car won't start, it can ruin your day pretty quickly. Most of us will face this at some point in our lives, whether we're a driver or a passenger, so it's worthwhile familiarising yourself with what to do.
Contents
Reasons your car won't start
Here are a few of the most common reasons.
1. A flat battery
A flat battery is one of the most common reasons a car won't start. It can happen due to old age, a broken alternator, or leaving the lights or electrical systems running while the engine is off.
What to do
You have a few options:
Try performing a jump start - this guide explains how.
Call your breakdown cover provider.
Contact a mobile mechanic who can test whether the battery needs replacing and, if so, do the job wherever you are.
Replace the battery yourself - find out how.
The average price of a battery replacement when you book through FixMyCar is £225.93.
2. Broken starter motor
Can you hear a single, loud click when you turn the key in the ignition? If so, you may be experiencing a problem with the starter motor.
What to do
You'll need to contact a mechanic for this one. The average price of a starter motor replacement is £384.39 when you book through FixMyCar.
3. Stuck steering lock
If you can't turn the key in the ignition, the steering lock might be jammed, which typically happens when one of the car's front tyres is wedged against a kerb.
What to do
You should be able to free the lock by moving the steering wheel slightly from side to side while trying to turn the key. If you can't move the wheel at all, push the brake pedal and slowly release the handbrake to let the car roll away from the kerb a little. Then, put the handbrake back on and try again.
4. Immobiliser
Your car's security system could be the thing preventing it from starting. If the immobiliser doesn't recognise your key, the engine won't start. This often happens due to a flat battery in the key fob.
What to do
The first thing to try is replacing the battery in the key. If that doesn't work, your key may need reprogramming, which is a job for a car locksmith.
The average price of an auto locksmith repair is £250.33, according to our data.
5. Fuel system issues
Several fuel system issues could prevent your car from starting, including a broken fuel pump and a blocked fuel filter. Unfortunately, there's no easy way to diagnose these problems.
What to do
If the fuel system is to blame, you'll need the help of a mechanic. The average price for this kind of repair is £210.04.
6. Flooded engine
Flooded engines aren't very common anymore because of the fuel injection system fitted to modern cars. When an engine is flooded, there is too much fuel and not enough air in the combustion chamber. It typically happens when a car is switched off too soon after starting.
What to do
Follow the advice in this guide to start a car with a flooded engine.
7. Spark plugs
Spark plugs need replacing every 100,000 miles or so. When they wear out, the engine might not start. Learn about the other signs of spark plug failure in this guide.
What to do
You can either change the spark plugs yourself or find a local mechanic to do the job for you. On average, a spark plug replacement costs £151.14.
8. Faulty alternator
The alternator charges your car's battery and powers the electrical systems. When it stops working, the battery will eventually go flat and the vehicle won't start.
Here are five signs of a faulty alternator.
What to do
Some alternator problems, such as a loose belt or faulty diode, can be repaired. Others require a replacement. Contact a mechanic who can advise you about the best course of action.
The average price of an alternator repair on FixMyCar is £524.99.
9. Low AdBlue
AdBlue is a fluid added to diesel cars to help lower emissions. You can learn more about how it works here. When you run out of it, your car won't start again and may require the help of a mechanic since some models need software to get going.
What to do
The best thing to do is avoid running out of AdBlue by paying attention to the dashboard warning that the tank is getting low. However, if you do run out, try topping it up first, and if that doesn't work, call a mechanic.
What to do if your car won't start
If you find yourself broken down at the roadside with a car that won't start and you can't find a way to fix it, you'll need to focus on staying safe, follow the procedure in this guide, and call for help from your breakdown cover provider or an emergency car recovery company.
Here are our top tips for avoiding a breakdown.
Frequently asked questions
What are the most common reasons your car won't start?
By far the most common reason is a flat battery - find out about the other common causes in this guide.
Can you jump-start a car in the rain?
It's safe to use your jump cables even when it's raining.
What tools should I carry in case my car won't start?
We'd recommend carrying the following essentials:
Jump leads
Empty fuel can
Jack
Still can't get your car started? We'll help you find a local mechanic to get you back on the road in no time.
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