Crayon smell

The DPF could be on regen and developing more than the 1,200 degrees it created when new. Could be burning paint or bed-liner. Maybe a leak has caused fluid to migrate to the DPF.

Ahhhh..... brings back the grade school kid in me ... opening that new and fresh box of Crayola Crayons the very first time of the school year! Nice memory. Thanks for sharing! (sorry about your problem though.)

might be a heater core with a very small leak.

Yup Rosmella has an odor for sure. But IMO it smells like oil.
I used the stuff once and it was annoying. Then a buddy had my truck for a while, we swapped trucks and he had the oil changed, called me saying he thinks it's leaking or burning oil. It was the Rotella smella.

If you use Rotella eng oil, it can have an odor for a while after an oil change.

Why? That stuff smell like crayons if yer Edsel was burning oil?

Good. Glad to know you guys are not using RayLube. :)

While it seems totally off the wall, our old 2006 SRT8 Charger had the same smell, but only when heat was on and only for a minute or so, like you.
And it may have been sporadic, like not all the time, and the last year or 2 never noticed it.
I swore there were a couple crayons that got shoved down the defroster vents or something, but never found out what it was and never had a problem.

FWIW, I just googled it and Mercedes of the same era as our old Charger (which was a Diamler/Mercedes chassis) had a crayon smell and it was some wax in the insulation somewhere.