Blue smoke at startup?

[ns954]

My 7.3L puts out blue smoke upon initial startup.It lightens up after the engine runs for a minute.After that it disappears.Seems to occur on cold startup.For example,today it was in the 40's and it was noticeable.The engine has 100k on the clock.Runs smooth,no unusual noise,good power.I just purchased the truck,and i don't remember seeing the startup smoke prior to my oil change.I used shell rotella and the level is right on the money.Any thoughts?When should i really begin to worry?Thanks everyone.

[Lord Tauk]

Sounds normal to me. Nothing to worry about.

When it gets real cold, you'll see a haze of white smoke of unburnt fuel until the engine warms up a little bit.

[todd]

wouldnt be running red fuel would ya??

[sldghamr]

i had blue smoke years ago. ended being my fuel pump was going out.

[ns954]

Hehe.No red fuel here.Although i have been tempted to............

[Lord Tauk]

If I take notice, mine usually puffs out a small amount black smoke when I first start it in the warmer temps, it also depends on what tune I start it in.

Every 7.3 I've seen usually has a little blue white colored puff once they fire, more noticeable in colder temps. Unless it's something excessive, it's just the nature of the beast.

[todd]

just askin dont know how true it is but have heard from several different sources that for what ever reason the red fuel can cause a blueish tint to the smoke