cold weather/coolant smell

Occassionally while driving, I get that sweet, tangy odor, usually associated with a coolant leak. It seems to happen only when it is cold outside and usually when I have the heat on (fan on high-still need to replace resistor).
I took it in for a leak check, the mechanic thought maybe I had a bad heater core or leak, but upon inspection and pressure test, he found no leak and the heater seems ok. He did say coolant was about half and cup low, which could just have happened over time, as I have not added any in the 2 years I have owned the car, and it was topped off when I got it.
The car hasn't done this before, and we can't find anything obviously wrong with it. Is this intermitten odor normal?

I get the funky odor smell also -- but just the opposite - when I run the a/c. The winters are much like the summers here in South florida. and at night sometimes the a/c needs to be on the lowest setting in order to cool it on a winters night. I can say i can count the times ive used my heater on my hands, and i still get the smell. Someone said it was my freon running low. I'm not a mechanic and i dont know much about cars, but maybe check that?

I would think if you have a heater core leak you would notice your windows getting greasy or grimey a little faster than normal - the coolant would eventually leave a film on the glass.

i don't believe intrigues use freeon..

Intrigues and any other late model w/AC use the R-134A refrigerant, not the R-12. And even if it were leaking into the car you wouldn't smell it. I've worked with a lot of automotive AC systems and never noticed an odor with these refrigerants. However some AC systems have a tendency to have a little mold or mildew smell when first turning on the AC in hot and humid conditions.

How hard is it to recharge the refrigerant? I have an extra can of R-134a sittin in my garage. Just wondering what the process is, what it involves and where i charge it at?

Does your AC work at all? AC work can be kind of tricky. Especially if you are adding to a partially charged system. The best way is to totally evacuate the system and suck it into a vacuum for a half hour or so before adding the proper amount of R-134A. You should also have guages with a can tap. Or if adding from a 30 lb bottle you should have a scale. And of course a vacuum pump to put the system in a vacuum.

However if you feel your system is a little weak and you want to try adding a can you would put it into the low side with the engine running.

Occassionally while driving, I get that sweet, tangy odor, usually associated with a coolant leak. It seems to happen only when it is cold outside and usually when I have the heat on (fan on high-still need to replace resistor).
I took it in for a leak check, the mechanic thought maybe I had a bad heater core or leak, but upon inspection and pressure test, he found no leak and the heater seems ok. He did say coolant was about half and cup low, which could just have happened over time, as I have not added any in the 2 years I have owned the car, and it was topped off when I got it.
The car hasn't done this before, and we can't find anything obviously wrong with it. Is this intermitten odor normal?
Folks, lets not fool around here.

Coolant, even in a vapour form is poisionous. I have had heater cores that leak slowly, just a few drips at a time, so a pressure tester shows everything ok, but they are still leaking.

Replace the core soon. Its not worth the risk to leave it.

you need to hook therefrigerant hose to the low side connection.this is ez becouse a charging hose only fits on the low side.but be careful not to over charge it.more does'nt always meen colder. it useally holds about 2 to 3 lbs.if you have a gauges charge it to about 35 lbs.