I have a 61000 mile 2004 6.0 diesel v/8. It smoked at idle and smoked more on acceleration. Lot of smoke. Greyish Black. It started right up, idled good, and had power. The two local Ford dealers in orange county both did diagnostic checks. The first dealer took a week to suggest that it had EGR cooler and injector issues.$2500 to fix. The second dealer took one day and called to tell me that the turbo, fuel injectors, air filters, fuel filters, possible ficm faults,,,,, etc. $6500 to fix. Neither Stealers printed any of the issues or recommended repairs on the diagnostic receipt. So,,,, after reading about egr coolers, oil coolers,turbo chargers,fuel injectors,ficm, and all the readings that show up on the different diagnostic equipment I decided to take matters into my own hands. After reading about all the different scenarios on this site I took a calculated guess and removed all the injectors and took them to Becs Pacific. They placed the injectors on the test bench and proceeded to find two of them to be defective, way out of tolerance, too much volume, and the other six cleaned and resealed. Placed them back into engine, fastened everything down by correct torque. Started engine. Smoked but after two minutes cleared up. Took for test drive one hour. Exhaust is so clean, no smoke. clean. runs XLNT. Thanks to all that contribute to this site......