get a coolant pressure test done to locate the leak. is it leaking outside? if so it could be MANY things, most common is a hose or the water pump.
try following the hoses from the anti freeze tank you should find your problem...
Could be the intake manifold gaskets are leaking.
if it rear air and heat it could be the line carring the antifreeze tho the back heater core.
smell of antifreeze and no visable leaks usually indicates that the heater core needs replacing
change your antifreeze fill cap.
Make sure it is full of coolant. There probably is a small leak causing the smell. Check it cold as sometimes it leaks cold but not hot.
Could be a few things. Does it leak antifreeze? if so, fix the part that leaks. If not, you could have coolant mixing with oil inside the engine, which burns it. check your spark plugs. If they are white, you are probably burning antifreeze - fix immediately. your exhaust will smell "sweet" as well if you are burning antifreeze.
Same color as what?
have you flushed your radiator or changed the thermostat it could be stuck
There might be a leak in the water pump, or in the radiator. Maybe even check the radiator hoses for cracks and leaks.
Some people say that the smell of hot antifreeze smells like mold. It could be possible you are smelling the antifreeze from the engine.
Oil/antifreeze mix is usually caused by head gasket leaks or valve cover gasket leaks.