White fog coming out of the AC vents is not normal and may indicate a problem with your car's cooling system. If you notice white fog or smoke coming from the AC, it could be due to one of the following issues:
Coolant Leak: The most common cause of white fog coming from the AC vents is a coolant leak in the heater core. The heater core is a small radiator-like component that heats the air before it enters the cabin. If there's a leak in the heater core, engine coolant can mix with the air, producing white fog or steam. Coolant leaks are a serious issue that can lead to engine overheating and other problems if not addressed promptly.
AC System Issue: In some cases, white fog might be caused by a problem within the AC system itself. This could be due to a refrigerant leak, which might produce a similar fog-like effect when the refrigerant mixes with the air coming from the vents.
Condensation: During humid weather, condensation can form inside the AC ducts and may be visible as white fog when the AC is turned on. This is typically not a serious issue and may go away once the AC has been running for a few minutes, as the system dries out.
Regardless of the cause, it is essential to have your car inspected by a qualified mechanic as soon as possible when you notice white fog or smoke coming from the AC vents. Coolant leaks and AC system issues can lead to further damage if left unaddressed and may compromise the safe operation of your vehicle. Avoid using the AC until the problem is diagnosed and repaired to prevent potential damage and to ensure your safety on the road.