In 2003 the very popular 7.3L was replaced by the 6.0L due to its inability to meet emission standards. The 6.0L, unlike the 7.3, has proved to be problematic. The problems began with the decision to sand-cast the engine block.
The sand enters the EGR and oil cooler and blocks the coolant causing a failure of the cooler. When the cooler fails coolant enters the cylinders (coolant being non-compressible) and causes a head gasket failure. From there it’s a domino effect.
The 6.0L uses torque-to-yield head bolts that further aggravates the problem by not maintaining the torque sufficiently and stretching.
These are just a few of the problems. The 6.0L Powerstroke relies on a hydraulic fuel pump. The high-pressure oil pump doubles as the fuel pump supplying high-pressure oil to the hydraulic-electric injectors.
The 6.0L Powerstroke uses a split-shot injection system that supplies a small shot of fuel a few degrees before the main shot. This lessens the knocking sound so typical of diesels.
Due to the nature of the beast (high-pressure oil pump) and the fact that they are cast in aluminum makes them prone to leaking over time and must be inspected regularly.
Care must be taken when purchasing a rebuilt high-pressure oil pump since the threads on aluminum deteriorate making replacement of the O rings ineffective in preventing leaks past the threads. Stay with a new pump considering the complications a leak can cause.
The life expectancy of the high-pressure oil pump depends on the frequency of the oil changes necessary to keep the viscosity constant. Diesels have a higher compression ratio than there gas counterparts and experience more blow-by past the rings. When compression passes the rings fuel and carbon dilute the oil thereby reducing its viscosity and ability to adequately lubricate properly.