Few things are more frustrating than turning the key, or pressing the start button, and getting nothing, a click, or an engine that turns over but never fires. The good news is that the noise your car makes, or doesn't make, tells you a lot about what's wrong. Here's how to work out why your car won't start, what you can safely check yourself, what a starter motor replacement typically costs in the UK, and where a car warranty can help.
First, listen: what happens when you try to start it?
The quickest way to narrow down the cause is to notice exactly what the car does when you try to start it.
| What you notice | Most likely causes |
|---|---|
| Nothing at all: no lights, no dashboard | Completely flat battery, corroded or loose battery terminals, main fuse |
| Dashboard lights come on but nothing happens | Starter motor, starter relay or solenoid, immobiliser, clutch or gear selector switch |
| A single click or rapid clicking | Weak battery (rapid clicking) or a failing starter solenoid (single click) |
| Engine turns over slowly | Weak battery, especially on a cold morning, or a tired starter motor |
| Engine turns over normally but won't fire | Fuel supply, ignition, sensors or, on diesels, glow plugs |
| Starts, then cuts out straight away | Immobiliser, fuel pump, sensors, or an alternator not charging |
| Grinding or whirring without the engine turning | Starter motor not engaging properly with the flywheel |
This is a guide, not a diagnosis, but it helps you describe the problem accurately to a garage or recovery service, which saves time and money.
The most common reasons a car won't start
A flat or failing battery
By far the most common cause, especially in cold weather. Short journeys, a car left unused for a couple of weeks, lights left on, or simply an old battery can all leave it too weak to turn the engine. Most 12-volt car batteries last around four to six years. Modern cars draw a small amount of power even when parked, so a battery that is fine with daily use can go flat if the car sits for a while.
A failed starter motor
The starter motor is a small but powerful electric motor that turns the engine over until it fires. It engages with the engine's flywheel through a small gear and is switched on by a solenoid. Starter motors wear out over time, and the solenoid or the motor's brushes are common failure points.
Alternator not charging
If the alternator has stopped recharging the battery, the car may run until the battery is drained and then refuse to restart. A battery warning light while driving is the clue. Our guide to alternator replacement costs explains how to tell an alternator fault from a battery fault.
Immobiliser or key problems
If the car doesn't recognise the key, the immobiliser stops it starting. A flat key fob battery is a frequent culprit on keyless cars. Many cars let you start them by holding the fob against a marked spot on the steering column or start button; your handbook will show where. Trying the spare key is a quick test.
Fuel problems
An empty tank sounds obvious, but a faulty fuel gauge can catch people out. A failed fuel pump, blocked fuel filter or faulty injectors can also stop the engine firing even though it turns over. Putting the wrong fuel in can cause problems too; if that happens, don't start the engine.
Ignition, glow plugs and sensors
On petrol cars, worn spark plugs or a failed ignition coil can prevent starting. On diesels, faulty glow plugs make cold starts difficult, as our guide to common diesel problems explains. A failed crankshaft or camshaft position sensor can stop any modern engine from starting, because the engine computer no longer knows when to fire.
Clutch or gear selector switch
Most manual cars won't start unless the clutch is fully pressed, and automatics need to be in Park or Neutral. A faulty switch can stop the starter motor working even though everything else is fine.
What you can safely check yourself
- Check the lights. If the dashboard and headlights are dim or dead, the battery is the prime suspect.
- Check the battery terminals for white or green corrosion, or a loose clamp. Only do this with the engine and ignition off.
- Try a jump start or a battery booster pack, following your handbook's instructions carefully. Some cars have dedicated jump-start points under the bonnet.
- Try the spare key to rule out a key or fob problem.
- For manuals, press the clutch fully; for automatics, check the car is in Park and try Neutral.
- Check the fuel level, and don't trust a gauge that has been playing up.
Don't keep cranking the engine for long periods. It drains the battery further and can overheat the starter motor. Try for no more than 10 seconds at a time, with a short break between attempts. If the car still won't start, call for recovery rather than risk causing more damage.
Signs of a failing starter motor
Starter motors usually give some warning before they fail completely:
- A single loud click when you turn the key, with the dashboard lights staying bright
- The engine sometimes starting and sometimes not, with no obvious pattern
- A grinding, whirring or screeching noise when starting
- The starter continuing to whirr after the engine has started
- Slow cranking even though the battery tests as healthy
- Smoke or a burning smell from the starter area after repeated attempts
Cars with stop-start systems put far more demand on the starter motor, because it restarts the engine every time you pull away from a stop. These cars use heavier-duty starters, which tend to cost more to replace.
How much does a starter motor replacement cost in the UK?
On some cars the starter motor is easy to reach from above or below and can be changed in under an hour. On others the garage has to remove other components first, such as the intake manifold, exhaust parts or a drive shaft, which adds labour.
| Repair | Typical cost (independent garage) | Notes |
|---|---|---|
| Battery and charging system test | Free – £50 | Often free at battery fitters |
| Standard 12-volt battery, fitted | £100 – £200 | Smaller cars at the lower end |
| AGM or EFB battery (stop-start), fitted and coded | £170 – £350 | Many cars need the new battery registered |
| Starter motor, small or family car | £250 – £500 | Reconditioned units cost less than new |
| Starter motor, stop-start system | £350 – £650 | Heavier-duty starter |
| Starter motor, premium or hard-to-reach | £450 – £900+ | Labour can run to several hours |
These are typical ranges at UK independent garages in 2026, including parts and labour. They are estimates, not quotes. Main dealers usually charge more, prices are higher in London and the South East, and the exact engine matters more than the badge. A good-quality reconditioned starter from a reputable supplier is a sensible, cheaper choice for most cars. Always get a written quote for your registration, and see our UK repair costs hub for other common repairs.
How to reduce the chances of a no-start
- Have the battery tested before winter, especially once it's four years old or more.
- If the car sits unused, drive it for at least 20 to 30 minutes every week or two, or use a smart battery charger or maintainer.
- Replace a weak battery promptly. A struggling battery puts extra strain on the starter motor and alternator.
- Don't ignore slow cranking or intermittent starting. They're early warnings.
- Keep up with servicing, including spark plugs and fuel filters at the intervals your manufacturer sets.
Our guide to making your car last has more simple habits that prevent breakdowns.
Does a car warranty cover a starter motor?
The starter motor is an electrical component that is commonly listed in mechanical breakdown cover, but whether it is on your plan depends on your cover schedule. Check the electrical section of yours rather than assume either way.
A sudden failure of a listed part may be eligible. A starter motor, solenoid or sensor that fails unexpectedly is the kind of fault a mechanical breakdown warranty is designed to help with, subject to the policy terms.
Batteries, key fob batteries and spark plugs are usually excluded. They are treated as wear or service items. A flat battery isn't a breakdown of a covered part. Our guide to what isn't covered by a car warranty explains the common exclusions.
Authorisation comes first. Don't let a garage start a repair before the claim has been authorised. Our guide to making a warranty claim walks through the steps.
On ClearPath Premium, each eligible claim is covered up to £3,000 including parts, labour and VAT, with labour up to £100 an hour and a £100 excess per authorised claim. Recovery up to £60 after a covered breakdown sits within that limit. See what's covered and how to make a claim, and always defer to your policy documents.
The bottom line
When your car won't start, start with what you can see and hear: dead lights point to the battery, a single click with bright lights points to the starter, and an engine that cranks but won't fire points to fuel, ignition or sensors. Try a jump start and the spare key, then call for help rather than cranking endlessly. Most starter motor replacements cost a few hundred pounds. To see the cover available for your car, compare our plans or read about a used car warranty.
