Stench from heater

For about 2 years as soon as I turn on the heater in my 1995 Avalon a horrible acrid smell pours out of my vents. It is so strong that I cannot use my heater. Last winter my regular independent garage (which is very dependable and honest) worked on this problem. They said they found the remains of a dead animal, cleaned it out, and put in an odor masking preparation. As soon as that wore off, the stench returned, maybe not quite as bad, but still really awful. Can anyone help me with this? I can’t use my heater, and winter is COLD. Thanks.

There may be more then ONE animal remains.

Try spraying Lysol…it may do a better job.

Agreed; you have trapped another poor rodent. Don’t let PETA find out.

This happens to me occasionally. I keep a bottle of Pine-Sol in the garage. Before starting the engine I pour a few drops into the fresh air intake in the cowl. This successfully masks the odor until it dissipates by itself. Try it – your choice of lemon, pine, or lavender.


…and in case this is an instance of mouse infestation, I strongly suggest that the OP do some online research regarding the Hanta Virus. A bad odor can be just the tip of the proverbial iceberg when mice are involved.

I hate to say it, but once you add the discomfort and potential health issues together it might be time to pay somebody to tear into the dash & duct work, pull it all out & sanitize it. This is a labor intensive job so there’s the labor bill might be higher than you want to go but you might want to ask. I’d include auto detailers among people to call.

I will say that I once had the “rotten milk” kind of smell in the vents of a van. I took both lysol and ozium (an odor killer rather than masker), ran the blower motor & shot as much of that stuff in through the fresh air intake as possible. After sort of “flushing” for a while, I closed down the blower & all of the vents to let a bunch of it sit in there. It helped a lot.