Strong Coolant smell in Cabin?

I live in Western PA (snow and 30 all day) and after along day of football, dislocated my shoulder, I hoped in my 94 sport and headed home. About 20mins down the road, I got this horrible smell of antifreeze/coolant in the cabin. Temp gauge never moved but I pulled over anyway. Popped the hood and found no leaks of any kind. I had the defroster on but wasnt blasting it. Hoped back in and drove home another 7 miles and it went away. Just wondering what the heck that could have been? Any ideas? Better safe than sorry.
Thanks guys and Happy Holidays.
(Don't worry, I searched 5 times before posting)

PS. 119,000 miles on the 4.0

Heatercore. More and likley it is. Is your heater blowing colder? You smell it coming from the vents? Or is the floor wet at all?

Sounds like a leak in the heater core.

I've noticed the same smell occasionally in my XJ as well.

Mine gets an smell once in a while but it's from under the hood. I have an intermittent tiny leak somewhere. Well, at least I did...I think I fixed it by re-seating the upper hose on the radiator and moving the clamp towards the end of the bung.

If it's inside, you're looking at a new heater core. And if that's the case, it sucks to be you, b/c you have tear the dash out to get to it.

There is a small tube in which the water from the condenser drains out to the road. This tube if missing will cause the water to blow against the firewall and cause a wet floorboard and the smell of mold etc. That and a spent heater core. In case it helps.