How to get your car ready for hot weather

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Driving car sunshine

Hot weather can bring your car to a steaming, shuddering halt. But a few simple checks can keep you motoring on even the hottest days

Glorious sunshine might make you keen to get out and about over the summer. But just as you might slap on some sunscreen to avoid sunburn, and carry a bottle of water to make sure you stay hydrated, so your car needs a bit of preparation to make sure it copes with the hot summer days.

Fortunately, there are a few simple things you can do to get your car prepared that don’t require the skills of a master mechanic – and they could make all the difference. Here’s how to help your car keep its cool when the weather turns hot.

Check the coolant level

Adding coolant to car

The cooling system circulates a mixture of water and antifreeze around the engine to keep it cool. Find the coolant tank in the engine bay (the owner’s manual will tell you where to look) and check if the fluid level is between the maximum and minimum marks on the side. Top up if necessary with a mixture of antifreeze and water, or with neat antifreeze of the right type (the manual will give details). Wait for the engine to cool first.

Modern engines shouldn’t need much topping up, so if the level has dropped appreciably, get a garage to check for leaks or other problems.

Inspect the radiator and hoses

Checking car radiator

Clear away any dead leaves or other debris from the grilles and intakes at the front of the car. Any obstructions here will prevent cooling air getting to the radiator, reducing its efficiency.

The radiator is the large rectangular component, usually silver or black, which is right at the front of the engine bay in most cars. Look for the large rubber hoses leading from it, which take coolant to and from the engine. With the engine cold, give each hose a good, hard squeeze and look for cracks opening up in the rubber – if you find any, get the hose replaced. 

Check other fluids

Car dipstick covered in oil

Oil contributes to cooling, and is vital for general engine health. The owner’s manual will tell you where to find the dipstick. With the engine cool, pull out the dipstick, wipe the end clean with a rag or tissue, re-insert it and pull it out again. The oil should be between the maximum and minimum marks. Top up through the oil filler on top of the engine, using the correct grade of oil. Don’t overdo it – too much can be as bad as too little.

Screenwash additive might be something you think of more in winter, but in summer it will help your wipers clean bugs and grime from the screen.

Tackle your tyres

Checking tyre pressure

If you’re planning a holiday getaway involving a long motorway trip with the car fully loaded, make sure your tyres are able to cope.

Check the tyre pressures using a gauge when the tyres are cold, or get a garage to check them. Low tyre pressures allow the tyre to flex more as it rotates, creating excessive heat that can make the tyre fail. That can be dangerous, or at the very least inconvenient.

Give each tyre a visual check, too. Look for cuts in the sidewalls and wear to the treads. If you’re towing, don’t forget to check your caravan or trailer tyres.

Ventilation and air con

Checking air con car

If you haven’t been using your car much recently and you’re planning a big trip in hot weather, check that everything works and fix any problems before you leave.

Try the fan, as they can seize up through lack of use. Check that the air con blows cold air. If not, it may need to be re-gassed, which is quick and cheap. However, it may have sprung a leak, which will need to be investigated.

If you have air con, a small pool of water might appear underneath the car in hot weather – it’s just condensation draining out of the system and nothing to worry about. 

Hot tip: the fastest way to cool a hot car

Your car’s been parked in the sun and it’s roasting hot inside. What's the quickest way to cool it? You’ll turn on the air conditioning, of course, but should you open the windows or not? 

The best technique is to open everything – front and rear windows, sunroof, the lot – and drive off. Make sure the fan is on high. After a minute or two, close the front windows, then wait another minute or two before closing the rears. This will use the air flow around the car as it moves along to help extract the hot air from the interior.

What to do if your car overheats

Car overheating

If the temperature gauge needle climbs into the red or you see steam coming out from under the bonnet, find a safe place to stop as soon as you can and turn the engine off. On a motorway, exit through the passenger-side doors and onto the embankment. Stay ‘upstream’ of your car in case it gets clipped by passing traffic.

Wait for the engine to cool, then check the coolant level – refill with plain water in an emergency. This may get you going, but get the cooling system checked by a professional as soon as possible.

Carry water and sunscreen in case you have to wait for help where it’s hot and there’s no shade.

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Photos: Getty Images

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