Hello all! New to the forum and relatively new to diesels. I recently purchase a 2011 F550 6.7 that has 104K miles on it. I purchased it from a utility truck dealership in PA about 2 weeks ago. It went thru their service department, fixed a few oil leaks, did a full service (all filters, fluids, etc). The truck has been great, but tonight I was heading up I-95 going along at about 70mph, when it just started losing power. I had my foot to the floor and it would barely stay at 60mph. I let off the throttle and made it off the nearest exit. While on the exit ramp I rolled back into the throttle and it was like it never had an issue with lost power. Had half a tack of diesel so I went to the gas station and topped it off. Back on the road again and it's like nothing happened. Very strange. Boost gauge was showing 20 pounds while it was losing power and wouldn't go over that. When the truck is running fine boost gauge will hit 40 pounds on hard acceleration and settle in at about 30 pounds when cruising on the highway. Thoughts? Also, I have a 2004 F550 with the 6.0 and that old beast feels like it has way more ***** than this 6.7. Just sayin'

 

maybe it was in regen

 

Define regen please.

 

That's when the truck uses DEF to clean the exhaust filter. However mine hasen't done what you describe. Run a vehicle health report and see what it tells you.

 

Wrong. DEF is not there for regen. DEF is there to reduce NOX emissions in the SCR substrate. During regen the truck injects diesel fuel in the exhaust stroke in order to heat the exhaust. The raw fuel ignites in the DOC to create high heat in the exhaust. This high heat is used to turn the soot that has collected in the DPF into ash before releasing it out the tailpipe.

 

I did a health report and nothing showing bad. We drove home from MD today and it did the same thing again on the highway but only once. Had it floored and wouldn't get over 60mph. Boost gauge showed about 25lbs. Ran like that for a few miles and then back to normal. I'm going to take it to my buddies shop on Friday and hook up his Snap on scanner to it and see if there are any pending codes.