1995 Grand Am

Driving my car yesterday 1995 grand am when temp gauge spiked into the red. I heard a popping noise & then smoke billowed out of the vents into the cab. It was anit-freeze smoke b/c of the sweet smell. Did my heater coil just die on me?

Just as a bit of background my car has always had a overheating problem, sort of. What I mean is in the 3 years I've had this car the temp gauge would always go into the red after driving for a while. The car has never overheated, or leaked anti-freeze. I've had it to a couple of mechanics and they can't explain it. Who ever owned the car before me apparently tore the motor down and didn't put it back together properly b/c a couple of the bolts that are in the head aren't the right bolts they are just hex bolts with some washers as spacers. It makes for a slight gap around the head, probably less than an 1/8 of an inch, but it seeps oil slowly. I've thought maybe this was the problem with the overheating but I was never sure and the mechanics couldn't seem to give me a straight answer on it. If I would've have noticed the bolts being screwed up I would never have bought it, but it's been a good running car. I've only had to put a starter and tires on it in all that time.