I had this problem on my 99 Ford Windstar and it was because we had a leak in a hose right buy the heater intake and it was sucking in the air from what that leak was putting out. We replaced the hose and the smell went away. Also another key indicator if this is the problem is that eventually your coolant will run out and you will lose heat in the van as the hose that needed replaced carried the coolant from one place to another. I know pretty much nothing about cars so this is just from personal experience
Oh a smell smell here a smell smell there Here smell there smell Everywhere a smell smell
you smell
Black powder- especially after being fired, has a very strong smell from the sulfur contained in it.
you would smell very dirty air that would mostly give you the plaque
Mushrooms shouldn't smell bad after cooking but then it depends whether you have burnt them or not? Hominy does smell bad sometimes but that is usually a sign of it being off or out of date.
the heater core is going out
usually you will get antifreeze smell and steam inside coming from defrost
if you can smell antifreeze you need to replace the heater core in the vehicle
Blown Heater Core - The heater fan blows past the heater core and if it has a hole in it your antifreeze ios being blown onto your windshield.
you probably have a leaking heater core....you can replace it or bypass it
leaking heater core
If there is the smell of anti-freeze, you're almost sure to be replacing the heater core.See "Related Questions" below for more
if you smell it inside, it's the heater core it has a leak.
Over time debris and other things can collect near the heater core, its possible that something small and plastic has fallen down through the defrost vents and gets hot when the vehicle is running. You may need to disassemble the heater and remove the items and perhaps vacuum it out.
Maybe the heater core is leaking.
thermostst is stuck
They usaually fog up the inside of the windshield when defrost is used, soak the pass side floor with coolant and smell of anti freeze when operating heater in any mode.