car wont start in cold weather

Why cars don't like the cold

Find how to keep yours happy in winter

It's a nightmare when your car won't start in cold weather. And with frosty mornings and freezing nights, it's more likely to happen over winter.

Find out why cars break down in the cold and what you can do to keep your wheels on the road.

Clearing snow off car windscreen

Top 5 reasons why cars won't start in winter

The top reason for cars breaking down in cold weather is battery problems. That's because cold weather affects the chemical process inside your car battery, making it harder for the battery to hold a charge. (You'll probably have noticed that other battery devices like mobile phones and digital cameras lose charge quicker when it's cold too.)

We looked at the most common breakdowns our mechanics were called out to between December 2018 and February 2019. Here's the top reasons for calling us:

  1. Battery-related (24%)
  2. Tyres (16%)
  3. Intake and emissions (8%)
  4. Starter and alternator faults (6%)
  5. Locks and alarms (5%)

Winter car problems range from issues with the fuel intake, like faulty pumps and fuel injectors, to electrical problems with locking systems. Thankfully, our breakdown cover can get you moving again.

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Why do cars break down more over winter?

Cars won't start in cold weather for 2 main reasons, both of which are related to battery problems:

  • Batteries are more likely to lose charge and go flat in cold weather.
  • Cars might be sat on driveways without being driven for periods over the holidays.

Batteries charge while the car's driving. So if you don't drive for a few days over the festive period, the battery can lose its charge. It's also more likely to happen when the weather's cold.

There are other problems which can pop up when the weather's chilly too. If you don't get your antifreeze levels right, you could have a problem with frozen screen wash or engine coolant. Plus your car might not start in cold weather if you haven't used the right viscosity of engine oil.

Find out more: 

With Battery Assist, we replace your battery the same day.

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Are there more breakdowns over Christmas?

We often see a spike in breakdowns over the festive period. The worst day for breakdowns is always the first working day of the New Year. People try to use their car to go to work, often for the first time in a week or more after celebrating Christmas, and find it won't start.

The first working day of the New Year is traditionally a busy day for breakdowns.

car broken down in winter with warning triangle

How to avoid a winter breakdown

Give your car a little TLC and it should start for you each morning, no matter how frosty it gets.

The most important thing is to keep an eye on your battery. Take your car out for regular runs (of half an hour or so) to keep the battery charged. Batteries only last about 5 years, so if yours is nearing the end of its life, invest in a new one before winter.

Here are 10 things you can do to keep your car tip top in cold weather:

1. Check your coolant level

Check your coolant level regularly and have your antifreeze concentration checked by a garage, before the cold weather sets in.

2. Use a screen wash additive

Use an additive in your screen wash all year round, but make it undiluted in winter. It'll stop your washer jets from freezing up. If you keep running the pump without any fluid coming out, you could blow a fuse that controls something more important.

3. Check your wipers are off

Make sure the windscreen wipers aren't stuck to the glass before setting off. And don’t leave them on ‘automatic’ in cold weather. They could be frozen stuck and try to start going when you turn on the engine. It could damage your wipers or you could blow a fuse, causing other problems.

4. Clear snow off ASAP

Clear snow from your vehicle as soon as you can. Leaving it for a few days will make it a lot more difficult to shift. Find out the best way to clear your car of snow and ice here.

5. Defrost locks and handles

If you get frozen door locks or handles, a squirt of WD-40 will help. And a light smear of Vaseline or silicone furniture polish on the door seals will stop them sticking too.

6. Don’t leave wet clothes in your car

The water in the air can make condensation inside the vehicle worse, causing misted up windows.

7. Wait to open windows

Don’t open your windows as soon as you set off. They may be frozen in the frames and could become detached from the mechanism. Wait until the car's warmed up so any ice has had time to melt.

8. Keep your car clean

It's good to clean your vehicle regularly in winter to remove corrosive road salt. But don’t blast water inside the brake drums or cables. If the temperature drops, you could end up with frozen rear drum brakes and handbrake cables, and you won’t be able to get moving.

9. Move off carefully

If you have an automatic parking brake, there’s a chance it won't release. With your foot firmly on the foot brake, release the electronic parking brake and ease your foot off the pedal, driving off slowly.

10. Listen to your engine

If you hear a ‘screaming’ noise when you start the vehicle, along with smoke and a burning smell, stop immediately. Either the water pump or alternator may have frozen and driving on will cause further, more serious damage.

Find out how breakdown cover can help you - breakdown cover guide.

We provide 24/7 roadside assistance.

Published: 22 November 2016 | Updated: 11 December 2019 | Author: The AA

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