OK just started resently, when i turn on my defroster smoke starts pouring out of all of the vents, and it smells sorta like burning anti-freeze? i have a 83 Z28 anyone have this problem?
And sometimes it does it without turning anything on????? by just turning the temp switch over to HOT it starts makin smoke?
could someone please help me winter is coming and without heat its gonna suck

 

Sounds like you have a small leak in your heater core, and it's burning.