Burning Smell

[Andrea K]

The past two mornings I have been smelling a burning smell, like burning wood, when I turn on the air in my car in the morning. It's usually around 40F in the morning and the windshield is always fogged up, so I turn on the heat right after I turn the car on and immediately get a strong burning smell. After 30 seconds or so I turn off the air as I can't take the smell, and continue on my way. A few minutes down the road I turn the air back on and the smell is gone. In the afternoon, on the way home from school (about 60F or so) I turn the air on and there is no smell. Is there anything that can cause this smell? I have not witnessed any smoke coming from the hood, but it is a rather strong smell. Could it have something to do with the car being cold because after it warms up the smell seems to go away?


Thanks,
Andrea

[SchnellE34]

Well if there is no smell when you turn on the air in the afternoon, I doubt it would be the blower motor. Try the heat in the afternoon to identify a smell then. Or try no heat at all in the morning, to see if something else is warming up and burning. If its only the heat, I would suspect it has something to do with your heater core. Just a thought. Someone else may have a better idea.

[Jr ///M5]

Andrea, have Jon change out your microfilter...or has it been changed? It could have a leaf or some debris that is getting heated up by the blower motor wheel maybe????

If you're feeling mechanical....here's the link, maybe your boyfriend can do it with your supervision...http://bmwe34m5.com/howto/microfilter_install.pdf

Hope this helps Andrea, good luck.

Jr

[Andrea K]

Thank you. I'll tell Jon to look into it ASAP :D

[zhandax]

I have noticed that if I hit the wrong button and turn on the compressor instead of the rear defogger with the heater running I get a burning smell. Have not traced it down yet, though.

[joshua43214]

Coolant burning off an exhaust manifold can have a burning smell, kinda like burning wood. Maybe a small coolant leak the only occurs when every thing is cooled down and contracted. Pull the micro filter and peer up in there as well as you can, maybe something crawled up in there and died on the heater core. usualy a leaky heater core will have a sickly sweet smell.