Smoke from HVAC vents

Smoke coming out of the vents is most likely coolant that is actually steam. It is odd that it doesn't have a smell because if you get real close to it, they almost smell sweet when it is coolant.

The HVAC system has a heater core inside of it that has a coolant going through it. As the coolant heats up and air passes over it through the HVAC housing it heats the air and then it comes into the passenger compartment. This is where the heat comes from in the vehicle.

So when this heater core leaks and the coolant heats up, it starts to steam and will come through the vents.

Have you gotten real close to the vents and tried to see if it smells sweet?

If this is actual smoke it should have an odor as well. Let me know what you find. Thanks