Hi folks,

I've been extremely busy with a new job, and have let my maintenance go to the barest level since I did my brakes this fall.

This week, I have had some really curious heater problems. I have searched the board and found similar incidents, but no in-depth answers. What has been happening is when I am driving in below-freezing temps, after the car has warmed to operating temperature, white antifreezy fog will pour out of all the vents. The heater is set to cold. If I turn the heater on and switch on the fan, the fog will fill the cabin and the windows will fog up.

If I run the heat long enough (~10 mins) the windows will clear and the coolant smell will disappear... until the next engine warm-up cycle.

Sounds like my heater core to me, but I would like to know why this is occurring with the heater valve set to cold. Would one of you knowledgeable folks please help me understand this problem?

Oh, also, I replaced an aftermarket black radiator cap with a Volvo green cap this afternoon, and experienced no problems; I wonder if the black cap was defective and hurt my core.

Thanks,

Ari