I'm not sure what is going on with my car. Since the weather here is so unpredictable, on the extremely hot days I use my AC but recently, I have been smelling something sweet coming out of the vents? Is this smell dangerous, toxic or an easy fix?

 

The heater core is leaking. It is quite toxic, but naturally it would be. All the liquids used in your car are toxic. The leak will cause your coolant to get low. If the car overheats, a lot of the time, it's the end of the line.

 

What he said. You also might notice that the windshield will start to fog up a bit at the bottom near the vents and it if you try to clean it off it will be kind of greasy. The leaking antifreeze does have a sweet smell and the anti rust and anti corrosion additives make it feel kind of greasy and difficult to clean off.

Make sure to keep checking your coolant level and not let it get low. This is something you need to address right away.

 

if your coolant level is not going down too fast, it can also be the O rings for the hoses into the heater core...

 

I vote o-rings for the heater core. Check your rear carpets to see if they are wet and sticky. The coolant will tend to flow back and under the carpet. Makes a mess. The job is a PITA to repair. The parts are cheap but the labor is horrible. My ribs and knees are still tender from bending over the pax side door sill.

 

I did the o-rings and about a year later the heater core went. It had a crack right where one of the pipes were welded. I probably put too much stress on it when I did the o-rings. You know its the heater core when it is dripping out the A/C condensation drain under the car.