The 7 essential car maintenance checks you must do this summer

Whether you’re looking forward to a European road trip, travelling across the UK or just going on impromptu days out this summer, don’t let a temperamental car ruin your plans.

While car maintenance is important throughout the year, there are certain things that are more likely to cause problems in warmer months. Below, we reveal our 7 top tips to keep your car running this summer.

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1. Check coolant levels

Intense summer heat means your engine has to work harder to stay cool, so we recommend checking coolant levels more frequently – particularly before a long journey.

If it needs a top-up, don’t assume you can skip antifreeze in the summer and just use water. Which? car expert Daljinder Nagra says: ‘If there's not the correct dilution of antifreeze in your car's coolant tank, it could cause engine damage when the weather starts to turn.'

When topping up, use a 50/50 mix of water and antifreeze (or whatever is recommended by your car’s manufacturer). And don’t attempt to unscrew the coolant tank's lid if you’ve just driven your car – the sudden release of pressure could end up spraying hot water over you. Instead, wait for the engine to fully cool down, then unscrew the lid slowly, allowing any remaining pressure to safely escape.

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2. Inspect your tyres

Your tyres are the only point of contact between the road and the rest of the car, so it’s vital to check them throughout the year. And in the summer, tyre degradation is more of an issue than you might think. Hot weather can also cause tyres to expand, which increases the risk of a blowout.

The intense sunlight can also cause tyre problems. ‘Parking your car in direct sunlight for extended periods can cause your tyres to crack, especially in summer months,' explains Which? car expert Dino Buratti. 'It’s a particular problem with cars that store their spare wheel on the outside of the car – that spare could be unusable when you really need it.’

As well as performing a visual inspection for cracks, bulges and other defects, you should also check the pressure on each tyre, including the spare. Inspect their tread, too – by law, car tyres must have a minimum tread depth of 1.6mm in a continuous band across three quarters of the width of the tyre.

See our guide on how to check (and change) car tyres for more advice – and if you’re in any doubt as to their integrity, get them checked by a professional. 

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3. Test your air-con

If you've been saving your air conditioning for the height of summer, you might be in for a nasty surprise when you need it the most.

Air-con units that haven’t been used for months have a tendency to develop mould or suffer cracked seals; the former will result in a musty smell, while the latter means gases may escape, leaving your air-con ineffective.

It’s best to use your air-con sporadically throughout the year and test it thoroughly well in advance of a long journey.

If it's not up to scratch, get it checked by your local garage. It might just need a quick re-gas (depending on your car, this usually costs around £50-£100). If you’re having to re-gas it more than once every couple of years, there could be a more serious (and more expensive) issue, such as a faulty condenser.

4. Stay safe in summer downpours

Sun, rain, wind, hail – you never know what the great British summer may throw at you. And if you’re on the road when there's a sudden downpour, you don’t want ineffective windscreen wipers blurring your view of the road ahead. 

As Which? car expert Dino Buratti explains, it’s a particular problem in the summer: ‘Your car’s wipers are much more likely to deteriorate in prolonged periods of hot, sunny weather, particularly if you usually park in strong sunlight.’

Visually inspect your car’s wipers and test their effectiveness with a quick squirt of screen wash. If your wipers struggle to clear the water, smear your windscreen or are showing cracks, get them replaced.

Windscreen wiper blades are usually fairly easy to fit, but for a small fee a local garage or car parts shop will do it for you. And don't forget to also check your rear wiper.

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5. Check your 12v battery

Dead batteries might be more associated with the winter, but they don’t like hot weather either. If your battery is already on its last legs, a sustained blast of hot weather might tip it over the edge.

An ageing battery can die suddenly at any time, but you can look out for warning signs such as it taking longer for your car to start and the interior light dimming while doing so. If you need to jump start your car, watch our video to find out how to do it safely, then get the battery checked by your local garage.

If you’re in any doubt as to the condition of your battery – or are planning a long summer trip – it’s best to get it checked.

As the summer holidays approach, you won't be to only driver looking to get their car checked, so aim to get any checks booked in well in advance of a long journey

6. Inspect your bike rack

The summer is great for bike rides, but if you're planning to go further afield and load bikes onto the top or rear of your car it's important to do a few checks first – especially if you’ve not used your bike rack since last summer.

Which? cars editor, Will Stapley, speaks from experience: ‘Only after I’d loaded four bikes onto my car last summer did I think to check the rack’s condition. I hadn't used it for months and on closer inspection rust had attacked a number of the joints, leaving the rack dangerously unsafe.’

If you're using a bike rack on top of your car, make sure the roof rack it’s attached to is also in good condition.

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7. Check your breakdown cover

No matter how many checks you carry out on your car, there’s always the chance something will go wrong. Having breakdown cover offers peace of mind, but check that it covers things like breakdowns at your home. Our research shows your car is most likely to suffer a breakdown at home, but cheaper policies often exclude cover for this. And if you’re taking your car abroad this summer, check your cover is valid for all the countries you’re travelling through.

You might even find you don’t need to purchase cover. ‘Most new cars come with a comprehensive form of breakdown cover, while older cars sometimes get a year’s cover if you service them at an approved dealership,' explains Which? car breakdown expert Maha Gadir, 'It’s also worth checking whether breakdown cover is already included in your car insurance policy or as part of a packaged bank account.’

We’ve compared all the major car breakdown cover policies on offer. To see which are Which? Recommended Providers, head to our guide on the best car breakdown cover providers for 2024.

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