Heater Help.. I smell coolant!!!!

[maka]

hope this is the right forum. anyway, for some reason my car smells like i am buring coolant, (the sweet smell ) I noticed my car smelling like burning coolant when the heater is on, after a while my car over heated(for the first time) and I added water(cause i did not have coolant at the time). I later noticed that when i turn my heater on, it smells a lot more like buring coolant. I tried to find any leaks in my cooling system, but no green stuff in the engine. i added more coolant and never over heated since, but i still smell the buring coolant when the heater is turned on. any advice will help. thanks.

p.s. i also added radiator sealing compound, when i added coolant.

[rogoman]

You may have a pin-hole leak in the heater core which is located inside under the dash. Check for any wetness in the carpeting.

[Defiant]

The crucial WHAT KIND OF CAR would have helped, but suspects will be as above, or a heater hose, or depending on WHAT KIND OF CAR, possibly a heater control valve.If it's the valve, pray you don't own a 240Z.Your mechanic-on-a-bottle may have sealed the leak until it can be much more inconvenient. And, has made diagnosis all but impossible.