Just got a 2012 F250 w/ 6.7 diesel a few weeks ago. When I first start it the air from the vents has a horrible odor. It seems to go away after a few of minutes, but right at first it is bad enough to about turn your stomach. Thought of the cabin filter, but find out there isn't one. Any ideas what could be causing this fowl stench?

 

Probably a dead rodent or frog, something somewhere in the duct work.

 

Maybe antifreeze leaking in the heater core? Sweet smell.

 

I had issues with my ac not cooling properly. Also had an issue on humid days especially when you first turn on the ac. The air coming out smelled like wet moldy socks. Bought new 2016 in dec.2015 and by mid june2016 the cab smelled of this odor. The ac smelled all the time but especially on start up of the ac. I did notice something strange one day I was waiting with the ac running while waiting on my wife. I had parked on a slight downhill. I used to work around heavy machinery and got in a habit of getting out periodically and looking around and I noticed that the ac was not draining. I'm thinking what's going on? My wife comes out and I move the truck to make things easier to put some stuff in the truck. I move to an area of flat ground. I then noticed that the ac drain was pouring. I'm guessing almost a quart came out all at once. I read somewhere that these trucks do not drain when parking on a downhill. If you are parking and leaving your truck on a downhill maybe some residual condensation is not draining out causing the odor. I have also read where it could be a mold issue from the condensation. I think there is some kind of mold remediation kit that can be used. I did not research the kit as I was able to get a replacement vehicle from ford.

 

I have the same problem in my new truck, the humidity in this area can get to the 80-90 percent range. I normally see it when I don't use the a/c for a while like after a cool spell when I use the heat. I would imagine the odor would be from some kind of algae in the a/c coil box but it passes quickly once I use the a/c, I don't even worry about it.