Replacing the coolant: when and why it's important

The coolant for the car radiator It's one of those components we often forget about, until one day the car's temperature starts to rise dangerously. At that point, it suddenly becomes very important. But there's no need to push it to the limit: with a little care, we can avoid serious engine problems. Let's see when to replace it and why you shouldn't put it off.

What is coolant really for?

It's not just "colored water." The refrigerant has three fundamental functions:

1. Cools the engine: absorbs excess heat and dissipates it through the radiator.
2. Protects from frost: Prevents water in the system from freezing in winter, causing damage.
3. Prevents corrosion: contains additives that protect the metal parts of the cooling system.

If it loses these properties, you risk overheating, breakdowns, or expensive engine repairs.

When to change the coolant?

There's no one-size-fits-all answer for all cars, but there are some signs and timing to look out for:

• Check the maintenance booklet:each car manufacturer indicates a recommended interval, usually between2 to 5 years old, or every30,000-60,000 kmSome newer models have long-lasting liquids, but they don't last forever.
• Observe the level and the color:if the liquid isbelow the minimum, top it up (with the same type already present) and check that there are no leaks. If, however, it has becomecloudy, dirty or has deposits, it's time to replace it. Fresh coolant is usually green, red, or blue and clear.
• Pay attention to the engine temperature: if the needle of the temperature it rises more than usual (especially uphill or in traffic), you may have a fluid circulation problemBefore blaming the thermostat, check the refrigerant.

Why is it so important to replace it?

Many people think that simply topping up the coolant when the level drops is enough, but this is a mistake. Here's what happens if you neglect the coolant:

• It loses efficiency: the additives degrade and stop protecting against corrosion.
• Deposits are formed: they hinder circulation and reduce cooling.
• Risk of overheating: The engine works poorly and, in the worst cases, can seize.

If you replace it promptly, it will cost you less than repairing the engine.

How do you replace the coolant?

You can do it yourself if you have some basic manual skills, otherwise it's best to leave it to a mechanic. Here are the basic steps:

1. Wait until the engine is cold: opening the radiator cap when the engine is hot is dangerous.
2. Empty the old liquid: There is usually a drain valve under the radiator.
3. Flush the system (if necessary): use distilled water to remove residue and limescale.
4. Fill with new coolant: follow the proportions indicated, usually 50% demineralized water e 50% concentrated liquid.
5. Let the air bubbles out: Some cars have a specific procedure to avoid air pockets in the system.

Which liquid to choose?

Not all refrigerants are created equal. Always check:

• the recommended specification(e.g. G12, G13, HOAT), because using the wrong type can damage the seals;
• if it is already premixedIt is ready to use, while others need to be diluted.

Coolant is inexpensive and easy to replace, but neglecting it can cause serious damage. Check it at least once a year and respect the replacement intervals.

A well-cooled engine lasts longer, consumes less fuel, and avoids unpleasant surprises on the road. It's worth spending five minutes on it, right?