The most common reason for the coolant light to stay on in a Vauxhall Astra is low coolant level. Check your coolant level regularly, and add more coolant if necessary.
Coolant Leak
If your coolant level is low, there may be a coolant leak in the system. Common locations for leaks include the radiator, hoses, and water pump. Inspect the coolant system for leaks and repair any leaks as necessary.
Faulty Coolant Sensor
The coolant light may also stay on if the coolant sensor is faulty. The coolant sensor monitors the temperature of the coolant and sends a signal to the engine control unit (ECU). If the coolant sensor is faulty, it may send an incorrect signal to the ECU, which may cause the coolant light to stay on.
Coolant Thermostat
The coolant thermostat is responsible for regulating the flow of coolant to the engine. If the thermostat is faulty, it may not open properly and allow coolant to flow to the engine. This can cause the engine to overheat and the coolant light to stay on.
Faulty Water Pump
The water pump circulates coolant throughout the engine. If the water pump is faulty, it may not circulate coolant properly, which can cause the engine to overheat and the coolant light to stay on.
