switching from Rottella t5 back to Motorcraft

[rattler64]

I was running Motorcraft 15w40 in my 2004 F250 6.0L and I recently switched over to Rotella T5 10w30. Can I go back to using motorcraft 15w40. Because I posted a thread about a burning oil smell while sitting still that was coming through the a/c vents, also smelled it standing next to it. I checked everything except the turbo, Im not leaking anything on the pavement and the dipstick shows the same everytime I check it. It started right after I switched to the rotella. So can I go back to Motorcraft. Thanks for all the help.

Rattler64

[pizza pig]

you can run saw dust through it if you really want to, all joking aside..... i would highly not suggest going back to the motorcraft oil. Maybe try 8oz of Rev X oil aditive and see if it cures your problem. Maybe it was some bad oil or something, because a lot of people are running this oil including me with zero issues. I say give it a little while depending how long you've had the oil in there. These trucks are sensitive to what oil is used in them; let it work through the system and see where it gets you

[Loubell]

I'm not a mechanical engineer, but I can't figure out how the viscosity of oil would have anything to do with a burning oil smell. What you are smelling could be from oil change spillage, an oil leak from the CAC boots, a power steering leak, a trans or trans cooler line leak, a transfer case leak, front or rear pinion seal leak (getting flung onto the hot exhaust).

A small underhood burning might completely burn off by the time the truck has fully warmed up. Start it and drive it for only about 5 minutes, shut it off. pop the hood and try to tract the smell or even smoke, if there is any.

[motorhead440]

Rotella has been called "Rosmella" for many years. The crankcase vapors take on an unusually foul smell when using Rotella. Its strongest right after the oil change then it gradually goes away.