The "antifreeze smell out the AC vents" would mean only one thing, you have a small leak in the heater core.
It is possible that the antifreeze is coming from a bad water pump. Clean the engine off. Watch it to see where the antifreeze is leaking from, as it could be a hose instead of the pump.
I would check the hoses leading into your radiator, and also the overflow for antifreeze. If that is not the problem, it could be your heater core. Your heater core might be leaking, you might have a hose leaking
If the heater has a sweet smell it could be that the heater core is leaking engine coolant. When the leak gets worse you will have a wet floor on the passenger side and the windshield will fog up when you turn on the defroster.
It depends on if you see the antifreeze leaking or it is just disappearing. If it is just disappearing then a bad head gasket or cracked head may be the problem. The smoking could actually be vaporized antifreeze. If that is the case don't run it until you can get it fixed.
Check the water pump. Examine it for traces of dried coolant that might be leaking out of the casting.
Antifreeze is typically green, but the newer stuff is "gold". If you're getting red liquid leaking from the radiator it's probably the transmission coolant line.
Your transmission fluid is probably leaking into your coolant
That's why is call a leak. Check all your coolant hoses, water pump, heater hoses, radiator, coolant reservoir, exec... Any freeze plugs exc. Could be your heater core is leaking. Let us know where you think the leak is coming from? Why do you think it is leaking. Do you smell antifreeze from the AC vents?
you might have a blown head gasket and the coolant is leaking into the cylender and the engine is burning it.
The overflow tank is either cracked or its overheating and leaking from the cap
If by water you mean engine coolant, yes. Loss of coolant, antifreeze, is a major cause of overheating.
Yes But: Breathing the anti-freeze fumes is not good for humans. Also running out of coolant and engine overheating will cause damage. If it's an emergency, bypass the heater core with a hose and clamps to route coolant back to engine.
there might be a leak some where in a coolant line. or maybe you have a leak in your radiator.
Look for leaking antifreeze/coolant. Usually you can see it leaking around the top of the engine. Also check your oil, if it looks milky it has been mixed with coolant and you intake manifold gasket is leaking. That being said, it is possible to have a leaking intake gasket with no sign of leaking antifreeze. Most intake manifold issues/leaks are coupled with poor engine performance and even sputtering and lack of power.
its probably leaking from somewhere else and dripping off at the tranny area. pressurize the coolant system so that you can detect the leak and go from there.
watch your coolant level because antifreeze is probably leaking in your heater core, another indication of leaking heater core is greasy film on inside of your windshield and it makes it hard to defrost.
Find the leak and replace the hose/part that's leaking. It's a good time to flush your coolant system, too.