I have a 2006 F250 6.0L. I live in GA and it has just started getting cold. I let my truck run in the morning for around 15 - 20 mins before I take off. It will hesitate real bad sometimes even when the temp gauges are normal. When I park during the day in 30 - 40 degree weather, it will act the same. Sometimes having no power going up small hills and I even see a light blue smoke cloud from the exhaust. It looks like diesel fumes and not EGR water vapor. Any suggestions? No mechanic can figure it out, because it will not give any error codes.

 

Winter fuel??
Have you tried putting in an additive during the winter months?

 

I haven't started using anything yet. Sort have been waiting on the mechanic to tell me something.

 

Thread moved to the 6.0L Power Stroke Diesel forum.

 

I would bet the turbo is sticking. Idling it for a long time is not adviseable (nor is it necessary).

 

What oil brand and weight do you use? Probably 15w40 non synthetic?

IMHO it's probably some injector stiction (search "stiction") or oil latching and won't always throw codes. You might try some fuel treatment, but it's probably NOT going to help your issues. You might try a product called Rev-x. It helps injector stiction tremendously in most cases. Do it at your next oil change 2-4oz bottles--$68 for a superduty. Might take it a few miles to work but it DOES work.