I have a 05 F350 with 109k miles. The other day i had white smoke coming out the tail pipe, so i cleaned the EGR, added (Sea Foam) to the fuel and crankcase and it stopped but I'm still losing coolant. Its not in the oil where is it going.

 

Probably going to be your EGR cooler. I would recommend doing away with it completely.

 

EGR cooler The inner pipe is probably cracked. Known point of failure. Someone makes an upgrade for it, a heavier duty one if you want to stick with the cooler. It's a bitch to take off and replace.