Cooling
Check and Top Up Coolant
Check the coolant level in the expansion tank on a cold engine, top up with the right coolant, and know the signs of a leak or overheating.
- EasyMost owners can do this with basic tools.
- 10 to 20 minutes
- Updated
General guide; check your car's handbook.
Safety first
- Never open the expansion tank or the radiator cap while the engine is hot. Hot coolant under pressure can spray out and burn you.
- Check and top up only when the engine is cold, after the car has stood for some hours.
- Coolant is poisonous and tastes sweet. Keep it away from children and animals, and wipe up any spill.
- Do not mix different types of coolant. Use the type your handbook names.
Steps
- Wait until the engine is cold. Park on level ground and let the car stand for some hours, ideally overnight. Open the bonnet.
- Find the expansion tank. It is a see-through plastic tank joined to the radiator by a hose, marked with MIN and MAX. Your handbook shows where it is. Do not confuse it with the screenwash or the brake fluid tank.
- Read the level against the MIN and MAX marks on the side. On a cold engine it should be between them.
- Look at the coolant. It should be clear and coloured. Brown, rusty or oily coolant, or a light brown layer on top, needs a workshop.
- Get the right coolant. The type is in your handbook. Choose one that meets it ("Parts for your car" below). Ready mixed coolant goes in as it is. Concentrate is mixed with clean water first - follow the label.
- Open the cap slowly. Cover the cold cap with a rag and turn it a little, so any pressure goes out, then take it off.
- Top up to MAX, not above, using the funnel. Refit the cap until it is tight.
- Use water only in an emergency. Clean water can get you to a workshop, but it weakens the coolant's protection against boiling and rust, so have the mix put right soon.
- Look for leaks. Check the hoses, the radiator and the ground under the car for drips or dried coolant marks.
- Check again after your next drives, with the engine cold. A level that keeps falling means a leak: see a workshop.
When to go to a workshop
Go to a workshop if you need to top up often, if you see coolant under the car or smell it, if the temperature gauge goes high or the warning light comes on, if there is oil in the coolant or white smoke from the exhaust, or if the fan does not run. An engine that overheats can be badly damaged, so stop as soon as it is safe.
Parts for your car
Choose your car and we open its Coolant & Antifreeze page.