I have a 2003 pontiac bonneville. When using the heater, there seems to be a burning smell on the inside and outside of vehicle. The smell is worsened by the fan setting, the higher the fan is the worse the burning smell. Any ideas? Thanks to all…
Can you smell the burning if you turn the fan on high but leave the temperature on “cool?”
The fact that you smell something outside the vehicle makes me think the odor is being drawn in, and not being produced in the HVAC system.
Is there an oil leak on the engine anywhere?
I haven’t tried it on a cool setting since it is freezing here. When I say outside the vehicle, I am referring to when I park it and get out you can smell the burning outside the vehicle and can tell that it’s coming from the car. When I had the car in for maintenance like a month ago they told me about some valves that had the smallest of leaks, that I would need to have fixed, but they told me it wasn’t an emergent, right that second repair. And like I said the burning smell worsens the higher the fan setting.
Open the hood after parking the car and see if you can locate the source of the smell. Also check the oil level. If the car is leaking or burning oil the level can get too low and cause problems.
If the smell were originating inside the heater you would be unlikely to smell it when you got out of the car.
Do you know which valves the mechanic says are leaking slightly?
I don’t know which valves. I’ll check the paperwork from that day and add to post if I find out. I understand what you’re saying about the smell not coming from the heating system itself.
The same thing happened to me. I was driving along and I smelled something burning. Then smoke came out of my vents. I pulled over and opened the hood, but saw nothing. After a little detective work, I discovered that dry leaves had worked their way into the vent system through the grill in front of the windshield. Once inside the blower motor housing, they were ignited by the blower motor resistor. It’s much more likely to happen this time of year. If it’s easy to pull the blower motor or resistor, you can vacuum the debris out. It also helps to keep the grill in front of the windshield free of leaves.
I forgot to ask…what did the burning smell like? If it smelled like a bon-fire, I’d go with my leaves-in-the-blower housing theory. If it smelled electrical, your blower motor may be on its way out.
The burning smells like oil on fire. Maybe plastic. Not the smell of something organic. The valve is a head valve gasket
Ohhhhhh…I get it now. I think you may be talking about a leaking valve cover gasket. It’s probably oozing oil onto the exhaust manifold. It’s an easy fix for a mechanic if he/she can get to it under all the hoses and stuff.