Hey everyone. Iv'e got an 06 R53 with 125K on it.

My problem is with the HVAC. When I turn the cabin fan on it doesn't smell weird.. when I use the A/C it doesn't smell too badly but when I kick the heat on... it smells metallic and horrible.... but as soon as I back the heat off on the temp control the smell goes away... happens at any fan speed... nothing is in the fresh air intake under the hood and the smell happens regardless of fresh air or recirculated air setting...I have the auto climate control and already changed my cabin air filter.. no change in smell.... any ideas? Thinking of spraying Isopropyl Alcohol into the cabin air intake with the heat running...

 

Hmm, maybe the smell is coming from the heater core?? Not really sure, but you could try flushing it out and see if that helps get rid of the smell.

 

A friend had that problem in their Honda. There was a dead mouse in the heater core.

 

Could be a decomposing body in the back seat or trunk?...

 

^^ that just made me burst out laughing. Too funny.

 

^+1

 

Depends on what the odor smells like. It could also be mold/mildew in the ventilation system.

 

If you did the cabin filter and changed it to the charcoal version, then I would check the fan itself or something rubbing with the fan for that metal smell , its a pain to get to. So it only comes on with the heat ?

 

I am used to this being "normal" if its not unbearabal sometimes anywhere where i turn on the heat i get a weird smell maybe its not as "normal" as i think. Id check the cabin air filter first than your fluids and angine bay for any deadbodys

 

Just to update everybody, I found the problem and a solution. I tried all kinds of sprays and foams and cleaners and changed my filters and nothing changed.

What finally fixed the smelly problem with heat was to replace my heater core to the tune of $65 from Rock auto, some coolant, and two hours of my time.

The old heater core had a putrid smell through the aluminum fins for some reason that nothing can or could take the smell out of, it was also slightly leaking a very minute amount. So I swapped in a new one with new clamps and Presto!

Finally clean smelling air again with heat and with air-conditioning!!

For everyone else though, I recommend starting with the cabin air filter, and reaching into the blower itself to make sure no to breeze or dead things are within it. My problem specifically had to do with smelly smells when I used anything but cold air conditioning.

Motor on!

 

Thanks for the update. Baked in must smell on the fins on the heater core , sounds like. Most of the time like you said its a dirty cabin filter or something living or dead in the fan.