Bad head gasket and/or cracked head.
possible leaking heater core
Your intake is probably cracked. I had the same problem as well as others on a 98 LeSabre. I could smell the antifreeze and the fluid leaked down.
Could be a few things. Does it leak antifreeze? if so, fix the part that leaks. If not, you could have coolant mixing with oil inside the engine, which burns it. check your spark plugs. If they are white, you are probably burning antifreeze - fix immediately. your exhaust will smell "sweet" as well if you are burning antifreeze.
depending on what collor is the smoke. it could be a head gasket blown burning antifreeze or bad rings burning oil
Burning antifreeze via a bad head gasket could do that.
you might have a blown head gasket and the coolant is leaking into the cylender and the engine is burning it.
It depends on if you see the antifreeze leaking or it is just disappearing. If it is just disappearing then a bad head gasket or cracked head may be the problem. The smoking could actually be vaporized antifreeze. If that is the case don't run it until you can get it fixed.
Yes antifreeze is sweet smelling, burning oil stinks and gasoline is, well gassy.
Sounds like a blown head gasket
It could be that your head gasket is blown.
head gasket at shop rates $300-$500
Thermostat sticking. Replace thermostat and gasket.