Not really sure, but I hope somebody can shed some light on this. 2012 Cruze LT, 1.4 l engine. Approx 50k miles. Love the car but the past maybe 2 months I have been adding anti-freeze to the expansion tank. Maybe a pint each month. Can't see any signs of moisture on belts, hoses or driveway. Does anyone have an idea ?
Water pump or coolant tank cap. This is a sign of one of these two leaking under pressure. Get a bottle of coolant dye and dump it in your coolant. Then you'll be able to find the leak with a flashlight.
Another source is the water outlet. A kind of "tree" where all the hoses meet up on the right side of the engine bay near the front of the engine. However, it's pattern is a leak followed by a catastrophic failure. Since it's been going on for two months, it's not my first suspect.
Note that the water pump is covered by an extended warranty. That's still good even if you've aged out of the powertrain warranty.