I am experiencing a coolant smell ONLY when the HVAC is turned to 72* or greater. I am also losing coolant, but don't know from where! I'm guessing heater core... is there a weep/drain hole in the firewall? and where exactly is the heater core located on this car? behind the glove box? or behind the center console?

i need to get this problem solved before old man winter hits.

Thanks!
Chris

 

Check your radiator first. I had this problem thinking it was the heater core and it was that radiator.

 

that would explain the loss of coolant, but what about the smell?

the car has 250,000 miles on it. things are bound to fail, lol.

 

i guess i'll just bite the bullet and order a new core

 

Yeah the smell only happened when I had the heat on too.

 

Agreed. I've had to replace a leaking heater core on all three of my S70s and all of them have far fewer miles than yours...