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  1. AA Cars
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  4. What to look out for under the bonnet of a car

What to look out for under the bonnet of a car

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You don’t need to be a complete expert on the inner workings of a car to keep it running smoothly. But it helps to know the basics and how to spot when something’s amiss.

Unless you own an electric vehicle, or you have a higher end model with an engine towards the rear, you’ll need to get under the bonnet to check out all the major elements that keep your car moving.

Identifying key areas

The main areas you need to keep your eye on are the oil reservoir, engine coolant, washer fluid, the battery and brake fluid reservoir – all of which are integral to keeping the car going. By checking each regularly,you’ll be able to see when problems appear or fluid levels start to get close to their minimum level.

Oil filler: Located on top of the engine, the cap has the outline of an oil can on it. The fluid itself is used to help all of the engine’s moving parts run smoothly, and failing to keep an eye on this will lead to damage of the pistons and gears. The oil level can be checked by pulling out the dipstick, which is normally located close by and is headed by a yellow ring.

Remove the dipstick, clean it off with an old piece of cloth or paper towel, and return it to the engine. Take it out once more and check the level – there should be ‘Max’ and ‘Min’ readings on the stick itself. Make sure it sits in the correct area.

Engine coolant: The clear reservoir is positioned close to the engine block and usually contains a brightly coloured fluid that’s used to prevent the engine getting too hot and the internal elements from deforming. There will be ‘Min’ and ‘Max’ lines to keep the liquid inside of, and you’ll need to make sure the same type of coolant is used as before.

Windscreen washer: This helps to clear your front and rear screens of dirt and grime, so keeping this topped up and reacting to any warning messages is important.

Battery: This gives the whole car its electrical power. By ensuring there isn’t any corrosion on the elements (the two metal points on the battery to which the car connects), you’ll safeguard against any potential faults from the battery.

Brake and power steering fluid: Both are similar looking containers, but the difference is the black cap on the brake fluid compartment has a hexagonal logo on it, while the yellow-capped power steering fluid reservoir will tell you what it ison top so you can tell the difference. Both need the fluids to be kept in between the ‘Min’ and ‘Max’ marks on the side of their respective tanks.

Easy to spot issues

Easy checks that don’t require a mechanic include keeping an eye on the fluid levels of the reservoirs for liquids such as the brake, power steering and engine coolant.

Checking the oil can also prevent any potential damage occurring to the inner workings of the engine. By keeping the oil level within the 2 marks on the vehicle’s dipstick will mean that it’s running with the correct amount. Too little and the engine could seize up and need an expensive service from a mechanic. Too much and it could seriously damage the parts inside the engine by over-lubricating them.

You can also keep your engine bay clean can help by making sure grime and grit doesn’t make its way into important fluid lines, like the brake and power steering reservoirs, when you need to open them up.

Inside the engine area, you’ll be able to check if there’s been any crash damage or alterations to the braces surrounding the engine.

Does your vehicle need a closer looking over to ensure that it’s working at its best? Why not try the AA’s own Vehicle Inspection service for that extra peace of mind

More on maintaining a vehicle

Dealing with minor dents and scratches

How to check your car is ready for an MOT

Spare wheels: Using, buying and maintaining

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