Weird exhaust smell in cab of new F350

[SecretSquirrel]

Occasionally get a funky exhaust smell in the cab. I'm assuming this is DEF smell during a regen cycle. In any event I don't think it should be entering the cab. Anyone notice this?

[Retired JSO]

I know this is of no help. We have 5500 miles on our 2018 F350, all but the first 300 miles has been towing. We’ve never experienced any such smell. I’ve also added 2, 2.5 gal jugs of DEF so I know it’s going somewhere. I’ve read on another site where someone has also smelled something and suspects DEF.

[jonessvc]

I have a 2017 F250 diesel and i picked un exhaust smell a couple of times before 20,000 miles. I have 76,000 on it now and never smelled it again.

[Lins]

How new is it? Not uncommon to be burning off stickers/oils etc. in the first few hundred miles.

[Sierra360PDEK]

Sounds like regen smell, are you getting the smell while driving or when you stop at a traffic light. Our Duramax will get pretty stinky when stopped at a light I'd the wind is blowing the wrong way during regen.

[BigRockr]

If it smells like an older, pre-emissions diesel, you have an exhaust leak before the emissions equipment. Mine smelled like that new and the techs found a clamp that wasn't seated properly. Has never smelled since. Kid said it wasn't unusual and figured that to be the case based on description. Not sure about regen smell folks talk about. Only time I ever noticed on two trucks was when I happened to reset mpg display. Mileage was crushed for 10-15 mins and then bounced back up. Flat terrain, not pulling, noted nothing else

[Grumpy7159]

I have a 2017 F350 diesel and have experienced the smell also. My dealer told me about it before I even drove it off the lot. I haven't smelled it since the snow started to fly but I could smell it once in a while when towing. No big deal.

[Skip12]

Im not sure how helpful this will be but our 2015 F359 developed a similar smell. The actual cause was that somehow the wire to the thermostat moved to a place it shouldn't be and started to melt creating a similar smell.

[Mikolow]

We have a 2016 F-250 and never have smells inside. After regents though it will smell stinky and hot when you step outside.
Interesting to hear that the one gentleman's mileage went back up after regen. Mine will go from 18 mpg (around town) to about 14 after regen and maybe recover to about 16 at most for the rest of the tank.

Regen while towing the 5er doesn't seem to have as much effect (how much lower than 11-12 can you go anyways!)

[SecretSquirrel]

Thanks everyone for the replies. I think it's related to the regen though there is no way to tell when it's doing it. The truck is new. Only about 1300 miles on it so far. Have noted the smell a couple time. Last time as pulling back in the driveway, could smell it in the cab. Left the truck running and when I got out the smell seemed to be concentrated around the front driver side wheel well. No where else around truck. (Nothing at the exhaust) Fair amount of warm air blowing out of there. (Wheel well). First truck with DEF so not familiar with it and the expectations.

[jtaylor1920]

I’d take it to a dealer. You really shouldn’t be smelling exhaust around the front wheel well. Also, if you want to see when you’re truck is going to, or is, in regen I’d suggest getting a CTS Monitor and plug it into your ODBII port. This isn’t a tuner, but really is some digital gauges.

https://edgeproducts.com/shop/insight-cts2