Ok, I've never been good at describing smells. I only recognize a few automotive smells - coolant, brakes, and gasoline. I'm hoping though, that somebody can help me identify a smell though.

As far as I can tell, I only smell this when the AC is on, and it's not on startup any more than other times, and it's not constant. It isn't the musty smell that ACs are known for, and even though it only seems to be present when the AC is on, I'm not convinced that the AC is the source. It's a hot smell, and it smells very close to a brake smell, but not quite the same (at least from what I can tell). I can't quite figure out what the trigger is for the smell. I thought it was after I braked hard, but just yesterday I smelled it mildly right after take-off. The front brakes are fine (I just replaced the pads and the smell was present before I did that), and the back brakes look good, though I haven't disassembled them. There is no leaks from what I can tell, and the transmission was just rebuilt (smell existed both before and after the rebuild). I have only smelled it while driving, and never from outside of the car.

Questions:
1 - Is it possible that the AC is producing a burning smell?
2 - Are there any areas of the vehicle that I wouldn't be able to smell when the AC is off?

I don't know what other information would be helpful, but feel free to ask questions or suggest experiments! :-)

 

It could be a/c PAG oil your smelling from a leaking evaporator, if you go the auto parts store buy yourself a small bottle of PAG oil so you can compare the smell, it kinda gives you a headache after a while and you only noticed when the a/c is on as the fan blows it past the vents,JJ

 

maybe it's a blower motor or control module that is overheating