06 6.0L shifts late & runs rough cold

[BassMan]

I have a 2006 6.0L 250 Super Duty. Ran like a champ until lately, just under 89k miles on it. When it starts, especially on cool mornings (mid 50s is the coolest so far), it won't shift out of lower gears until high RPMs, and it seems to be running rough at those higher RPMs too. By the time i've driven a few miles, all is fine, and she's good the rest of the day. Any ideas? Thanks!

[BassMan]

Anyone? thanks!

[redcycle13]

Take this to the top.

[Hardline]

Have you every had your truck flashed. Sounds like you do not have the latest inductive heating flash. Had a buddys truck doing the same. Was a little hard to start and shifted terrible for about 1-2 miles. I sent him in to get the latest flash and all was better. JJ

[huhner5]

Its the way they are... need to be warm before driven hard... Nothing is wrong with your truck

[Hardline]

Originally Posted by huhner5

Its the way they are... need to be warm before driven hard... Nothing is wrong with your truck

Not with the newest flash. JJ

[Dave]

Originally Posted by Hardline

Not with the newest flash. JJ

Im thinking I have to go get that flash. But the downside is you have to order new tunes afterwards

[Hardline]

Originally Posted by Dave

Im thinking I have to go get that flash. But the downside is you have to order new tunes afterwards

Yea typical symtoms are kinda hard to start almost like it was run out of fuel. It kinda strumbles when it starts. Then if you take off before say 3-4 min of idle it will go up to around 3 grand to shift. Almost seems like the tranny is slipping. That is what my buddies 06 was doing. I told him to get it flashed and he said all is better now. He does have an SCT but I do not think he is using it anymore though. JJ

[Dave]

Mine stumbles for a minute if I dont let it warm up a little when its below 30. After about 4 blocks its normal though. Its worse in some tunes than others

[BassMan]

Mine started and ran fine, it just wouldn't shift until hi rpm. They did a reprogram of something, said it needed to be updated, and it has been fine ever since.