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Oils and coolant

Engine oil

Oil is necessary to lubricate your engine. You need to keep the oil at the level recommended by the vehicle manufacturer. Check regularly and top up the oil when necessary, especially before a long journey.

Ideally you should check the oil level every time you fill up with fuel.

How to check the oil level

The dipstick will tell you the amount of oil in the engine.

Some manufacturers recommend that you check the oil while the engine is cold, whereas others suggest you check it while it’s warm. Your vehicle handbook will give you this information.

You’ll need a clean, dry cloth to wipe the dipstick.

  • Ensure the vehicle is on a level area and not on a slope.
  • Look for the dipstick on the engine block of your vehicle.
  • Take particular care if your vehicle is fitted with automatic transmission.

There may be an additional dipstick for checks on the level of transmission oil. Consult the vehicle handbook.

Oil changes

Follow the manufacturer’s recommendations. Remember to have the oil filter changed at the same time as the oil.

Oil is toxic and, if it comes into contact with skin, can cause skin problems.

Use protective gloves or a barrier cream and always wash oil off your hands immediately.

Keep containers storing oil out of reach of children.

Oil use

The amount of oil an engine will use depends on

  • the type of engine
  • the amount of wear
  • how you drive.

Don’t

  • run the engine when the oil level is below the minimum mark
  • add so much oil that the level rises above the maximum mark. You’ll create excess pressure that could damage the engine seals and gaskets, and cause oil leaks. Moving internal parts can hit the oil surface in an overfull engine and may do serious or even terminal damage.

Warning light

If the oil pressure warning light on your instrument panel comes on when you’re driving, stop as soon as you can and check the oil level.

The oil in your engine has to perform several tasks at high pressures and temperatures up to 300ºC. It helps to

  • resist wear on the moving surfaces
  • counteract the corrosive acids formed as the hydrocarbons in the fuel are burnt in the engine
  • keep the engine cool.

Over time the oil will become contaminated with combustion products, metal particles and moisture. Regular oil and filter changes are necessary to ensure the engine is protected by clean oil.

Make sure you always use the lubricants recommended in the vehicle handbook.

Coolant

Most vehicles today use a mixture of water and anti-freeze to make up the coolant. This stays in the radiator all year round and helps to keep the engine comparatively cool while it’s running. The anti-freeze stops the coolant from freezing in cold conditions.

The anti-freeze also contains a corrosion inhibitor, which reduces rust and oxidation and prolongs the life of the system. In cold weather, keep the recommended strength of anti-freeze. Have it checked at least annually – late summer or early autumn is best.

You should check the coolant level frequently, particularly before a long trip, topping it up as necessary. Look for the high/low level markings on the header tank, where one is fitted. The need to top up often might indicate a leak or other fault in the cooling system. Have it checked by your garage or dealer.

It’s a good idea to carry a spare supply of coolant in your vehicle.

Warning

  • Never remove a radiator or header tank cap when the engine is hot.
  • Never add cold water to an overheated engine; let it cool for a while first.
  • Don’t overfill or the system will blow the excess out as soon as it warms up.