I discovered, upon random inspection, that my Chevy's coolant reservoir was empty. It has just made 100 000km. There was no leak I could detect. The car is rarely used as I stopped working. I topped the coolant with just under a litre of pure water and drove for under 50km. The reservoir was empty again. I am afraid to drive the car as I don't want to damage the engine. There was no overheating nor flashing lights. Was it right to have topped up with water? The car has never missed a service but recently serviced by a new company after GM left South Africa.
Problem solved. The leak was on the coolant reservoir. For days it was undetectable until I took it to the service company. There, the leak burst for everyone to see before inspection. It was replaced and filled with coolant. It looks like most Cruze vehicles develop similar issues after five years on the road, according to service technician who attended to my car.