Many things can cause a burning smell under the hood of your car, if the smell is accompanied by smoke you are most likely looking at a fluid leak dripping onto something hot and burning off. If it smells sweet this would be a sign of a coolant leak. A ozone type smell would most likely be caused by a burnt clutch (standard transmission) or brakes hanging up and staying applied. burnt clutch smell would be expected if you have a new driver learning to drive a stick. An exhaust leak would smell, well, quite frankly like exhaust which is a dangerous gas to be inhaling (CO2, CO, etc). either way if your car is smelling funky you should really have a professional auto technician check it out to prevent damage to your health, the environment or future damage to your vehicle.
The new car burning smell is probably just the oils burning off the engine. As the engine warms up for the first time, it will release a odor that smells like something is burning.
when changing the oil sometimes oil can be spilled on the engine block. as your engine heats up it causes this smell. it is completely normal
Several thing scan cause a burning smell from a car A/C. One cause can be that the compressor is burning up. Another possibility is a wiring shortage.
mine did this too. it was my thermostat. it was such a terrible smell and whenever i used my heat in my car i smelled it too. the thermostat is a pain.
because the fan belt is burning
The engine is burning oil.
Any smell from the car vents is unrelated to the AC system unless it is an antiseptic smell. Generally, the smells are environmental from your engine compartment, where the fresh air is taken from. If you smell something burning from the vents, then something is heating up to much under your hood. Check your compressor for a worn clutch, or oil leaking onto the exhaust manifold.
Because it's hot, it burns gasoline, and there are plastic-coated wires.
A burning smell from a car's brakes means that you are braking very hard or there is a electrical short circuit in the car. Another reason for a burning smell may actually be coming from the car's heater.
If the car is a manual and you are riding or slipping the clutch it could be that. Otherwise if you have been real hard on the brakes lately they can create quite a smell aswell.
if the engine is smoking and overheating the head gasket is blown or you popped a freeze plug
If there is an oil leak inside the engine compartment of the vehicle. The defroster could have some of the smell go into the cabin of the car. The engine should be checked for any oil leaks.