SO my wife has had her 2008 LX for about 3 years now, and ever since she baught it, there has been a HORRIBLE smell from the HEAT ONLY (ac dosent smell) Does anyone know what this could possibly be? I heard everything from AC condenser, to heater core. Its NOT the carpet as the dealer suggests. Seems like the smell is alot worse on the floor setting, but it is noticable on the upper vents too. We have been trying to pinpoint this smell for quite some time.
This car was a rental in Texas, as we got a great deal on it, and it has been a great car minus this smell. Could this be from the heater core?
Anyones suggestions would be a great help!

 

Check the cabin-air filter? But it seems like that would be the same regardless of heat vs. AC.

If you remove the blower, I don't know if you can get a good look into the ductwork. There's air-blend doors that operate along with the heater valve. So the air ducts that flow through the heater core can actually be closed off during hot weather AC operation.

Does it smell like mold or mildew? Or maybe a dead mouse?

 

My initial thoughts would also be the cabin filter (unlikely, but probably needs to be changed anyway as it is a "routine maintenance" item) or something in the heater core or ductwork as jimblake suggested.
An old story my dad told me long ago also popped into my head: when his brother got married, his friends did the customary pranking at the reception where they "decorated" his car. Anyway, they put sardines in the vent ducts (in addition to other things.) they were never able to get the fishy smell to go away. Ever.
Unfortunately, if the cabin filter is changed and the smell remains, You will likely have to get into the ductwork or the heater core and look for a dead mouse...

 

Honestly its like cat pee...WHo knows who did what given this car was a rental.
So sounds like the best thing to check would be the heater core...Or blower?(under the glove box) I have heard if the drain plug for the AC is clogged this can be a problem too. Im almost thinking can something be put into the heater core? I just think its fishy given that it ONLY smells on the heater. Ac smells fine..so that would rule out a few things. Ill have to do a search on how to inspect vents...I dont think this will be an easy job? But for a rental car, we had 0 problems with this car, so we hate to get rid of it just for that fact(in addition its just about paid off)
Does anyone have a link as to where the Heater core is located? Any ideas would be helpful! Thanks guys!

 

Check out hondaautomotiveparts dotcom. Put in your car info, then look at heater components. They pull diagrams from the shop manual and put then online. I've learned a lot from that site (thanks to JimBlake for showing it to me years ago)

 

Hot air will help evaporate any compound that smells, where cold air may not.

Removing the heater core is a major pain. You may want to remove the cabin air filter, turn on the a/c, and spray a heavy dose of lysol in there.

Also check for debris in the a/c drain hose. You may be getting midew in the a/c evaporator.

 

Clogged AC drain hose can make it smell, but I'd expect it to be the same for heat or AC. Still, check that & clear it out if it's blocked.

"http://www.hondaautomotiveparts.com/auto/jsp/mws/prddisplay.jsp?inputstate=5&catcgry1=ACCORD&catcgr y2=2008&catcgry3=4DR+LX&catcgry4=KA5AT&catcgry5=HE ATER+BLOWER"
(I'm not supposed to use an ACTIVE link since they're not sponsors)

If you can remove the blower unit (#4) you might be able to spray the Lysol in there a bit better.

 

Thanks for your help, i couldnt get this link to work, but this weekend im gonna try to check the evap hose, and remove the cabin filter and give it with lysol.

 

Sorry about the link, maybe it only works if you've gone through the following process...?

www dot hondaautomotiveparts dot com
click "parts"
put in your car's information
category = HEATER BLOWER

 

Thanks Jim...Im looking into it now!