I have an 04 F350 Lariat PSD...crew cab, short box,.....it has never let me down but I have had the Turbo changed 4 times..the EGR twice... You will find unlimited advice,some good some nonsense.
www.theDieselstop.com or Ford doctors diesel technician (search google).........I have been told that the reason I have problems with my turbo is that I dont drive it enough and dont get it hot enough...which I dont...had a resident mouse in the engine compartment for two years.(its 41/2 years old) I have 49000 miles on it and about 35000 of them where towing.....it has to cool down by idling for at least 5 minutes after a long drive...otherwise the bearings in the turbo will melt...and I use 6 oz of cetane every third tank fillup.....helps burn the fuel cleaner and hotter which is good for the EGR and Turbo....You might try and find out who owned it and contact them to see how they drove it....if they didnt have any problems then they must know what to do....