Why does the cooling system kick in after a few miles on my peugeot 306?

The cooling system is designed to keep the engine from overheating. When the temperature of the coolant reaches a certain level, the thermostat opens and allows the coolant to flow through the radiator, where the air flowing through the radiator cools it down. The coolant then returns to the engine and is recirculated through the system.

If the cooling system is working properly, the thermostat should only open when the engine needs to cool down. However, if the cooling system is malfunctioning, the thermostat may open too early, causing the engine to cool down too quickly and the cooling fan to kick in unnecessarily.

Some possible causes of the cooling system malfunctioning include a faulty thermostat, a clogged radiator, or a water pump that is not working properly. If the cooling system is not working properly, it is important to have it repaired as soon as possible, as overheating can cause serious engine damage.