1993 Ford Tempo Engine Smoking & Making Noises

Air Conditioning problem
1993 Ford Tempo Automatic 85,000 miles

Hi!

I have a 1993 Ford Tempo. The other day I had the car idling & the air was on, and all off a sudden it started to make this rumbly, buzzing sound (like the buzz of a washing machine telling you it's done). It also smelled funny, sort of burned and chemically. It happened a few times - I didn't realize it was coming from my car - and then noticed there was white smoke billowing from under the engine. It happened every time we gave it a little gas and would shoot smoke out. It was coming from the middle to front left side of the engine.

Basically, I was wondering if this is the AC Compressor, a belt that's out of whack, etcetera. Two people have told me it's a belt and then a family member's sketchy mechanic told me it was just the air compressor (he just drove it around for 2 hours, told me there was nothing wrong, and then I explained what was happening and that's when he came up with the AC Compressor). I don't want him to fix it and ignore the real problem if it's something more.I've been researching failed AC Compressors and haven't found anything that included smoking.

The air still works fine, as well - ice cold. And the car wasn't overheating either.

Thank you so, so, so much!