sluggish in the morning
 

hello all, i have a 2003 F250 powerstroke 6.0. i am new to the diesel world and could use some help please. i changed the oil in my truck the other night and noticed its very sluggish in the morning after sitting all night. i use Rotella t 5w 40. this happened once before but i just kinda blew it off. asked a buddy about it, he told me the engine runs off heat and compression and to let it warm up a bit longer. well i have been doing that but today after starting it and letting it run for about 10-15 min i got in the truck to leave, put it in gear and it wouldnt move. i put the hammer down and got a very slow crawl out of it. after crawling out of the parking lot she picked up a bit. shifting was hard (like it would slam into gear) after about 10 min of driving everything ran fine. i have know idea what could be wrong and in need of help. im not much of a mechanic so if it can be explained to me that would be great. its a f250 powerstroke 6.0 i have a sct tuner (street) tune. thanks!

Start by trying to read codes, if any. Could be a number of things. Start there though. They do run on heat and wont run to full potential until warmed up. Cold oil doesn't really let the turbo spool very freely either, which is why once they're warmed up they just seem to move so much easier.

thanks for the reply! i will check the codes tonight and see what i get. i was talking to a guy from work and was told due to the colder weather we have been having it could be the fuel is gelling up. i dont have a fuel tank heater, does this sound right at all?

If it was gelled, it would only run worse the more you tried driving it. Anytime I've had issues with the fuel (mine froze, but never actually gelled, I run additives), it would start and idle fine in the driveway without issue, but as soon as I tried driving down the road it couldn't keep up with the demand for the volume of fuel needed and would slow down and stumble and barely keep an idle.