Gone in a puff of smoke???

So...this is a one time thing???

Your computer may have been in uncharted territory, speed wise. If it does this again, maybe worry.

I have a 2001 and it had one episode like that after a complete tune-up. After that, it has run flawlessly.

Good Luck

Thank you sir...all suggestions are greatly appreciated. R Buck

Did the check engine light come on, or maybe flash during the event? If so, there is data logged in the PCM that would be of great value to this mystery. Most likely what was causing your vibration was a cylinder, or cylinders misfiring from loose carbon in the engine fowling the spark plugs. The smoke was the carbon coming out and being burned in the catalytic converter.

Sounds like miss firing to me too! I would suggest you have the computer memory scanned for trouble codes. I have seen several issues with late model Fords and their spark plugs.

"This truck had been sitting a while and usually when driven, only in city traffic a low speeds."

I'd put some Seafoam in it and take that puppy out for a 30 minute or better drive on the interstate before I did anything else. Stretch it out!

http://www.seafoamsales.com/motor-treatment/index.html

Almost gotta be a misfire. some of these are affected by an injector recall.

BUT, and that is a big BUT, what was the vibration before the puff? I was sure it was a bum tire, and then the puff and the vibration is gone. And, I have to add there was mild odor like from a dragging brake pad or drum.

I used to visit my grandmother every six months and invent some reason to take her Torino for a drive.

Once out of sight I'd hit the highway on-ramp and nail it. Months of built-up carbon would shake loose leaving a cloud behind me. She always thought it drove better after my visits.

I'm voting for a one-time, monitor and don't let it coke up like that again.

The smoke emission suggests misfiring.

However, the effect of this would most likely be a 'bang' i.e. a short duration of force as the gaseous mixture forces through the constrained tubing of the exhaust line whose radius has been sufficiently reduced by the build-up. A vibration on the other hand trancends a longer duration with oscillatory motion.

A lot can cause vibes : Bent rim, poor wheel alignment, sticking brake calipers.

Did this happen only once?