I have 2003 6.0l powerstroke and i get white smoke on morning start ups.THE warmer weather less smoke and colder weather more smoke. I checked glow plugs by ohm them out and checking amps. theGPCM seems good to. what else is there to check?

 

the outside temp.

most diesels will smoke white when cold. if it smokes white after you drive it and get it up to operating temps, then there's a problem.

for piece of mind check your fluids and if all seems normal, it's just the nature of the beast.