I have a 1995 F-350 with the 7.3 powerstroke. It has about 180,000 miles on it. When I start it up in the morning it produces a big bluish cloud of smoke with some white mixed in. The white goes away bu the blue tinge remains until it warms up then I do not see anything coming out of the exhaust.
Of course I believe the blue is oil related and the white from excess fuel.
I would ordinarily think that it would be worn rings if the blue smoke is always there but it isn't. If it were a gas engine I would think bad valve stem seals but not sure of the valve arrangement in diesels. Could it be a problem with the turbocharger?
On warm days after sitting most of the day when I re-start there is a minimum of blue. On colder days it lets out another blue/white cloud.
The truck seems to run good I have had it for more than a year.