The cooling system circulates a mixture of water and antifreeze through the engine and radiator. It carries heat away, prevents freezing, and protects internal parts from corrosion.
Low or old coolant is a common cause of overheating and expensive engine damage.
How to check the level
With the engine cold, find the coolant expansion tank — a translucent plastic reservoir with “min” and “max” marks. The level should sit between them. Never open the cap on a hot engine; pressurised coolant can scald.
Topping up
Use the coolant type specified in your owner’s manual. Different chemistries (often colour-coded, though colours are not standardised) should not be mixed without checking compatibility. Pre-mixed coolant saves you measuring water and concentrate.
Signs of a problem
- ▸The level keeps dropping between checks
- ▸Puddles under the front of the car, often sweet-smelling
- ▸The temperature gauge reading higher than usual
- ▸White, sweet-smelling exhaust smoke
- ▸A heater that blows cold air
Replacing coolant
Coolant’s corrosion inhibitors break down over time. Many modern long-life coolants last five years or more; older types needed changing every two to three years. Check your service schedule. A coolant flush is usually done by a garage, as old coolant must be disposed of properly.
Keep it away from pets
Antifreeze is toxic and tastes sweet, which makes it dangerous to pets and children. Wipe up spills, store containers securely, and dispose of old coolant at a recycling centre.
CAUTION: This is general automotive information, not professional mechanical advice. Always follow your vehicle manufacturer’s specifications and service schedule, and have brakes, steering, tyres, and other safety-critical systems inspected by a qualified mechanic.