I have a 2018 f150 4x4 with the 3.5 EcoBoost. When I have the heat or ac on and the vehicle is STATIONARY you can smell some sort of burnt fluid or exhaust smell inside the cab. If the truck is moving, you cant smell it. Only when its stopped at a light or stop sign or something. They have fixed 2 separate trans leaks (1st the trans pump 2nd the trans cooler) and it still hasnt solved the problem. The last time I took it in they said theres zero leaks anywhere. So if its not fluid leaking on the exhaust somewhere. What the HELL could cause this problem????? Anyone ever hear of this problem?

 

Sorry to hear that. First time I hear of such a problem. How many miles? And build date? Tranny issues are not that common, but have read about several... but never a smell inside the cabin, but what kind of odor you have? Can you tell? Must be frustrating indeed. Good luck.