2003 Powerstroke

The Ford 2003 powerstroke diesel engine is actually not one exact model of diesel truck.  The U.S. Congress passed new emissions regulations around that time, and, in June of 2003, Ford changed the powerstroke series diesel engines, which are manufactured by Navistar International (formerly International Harvester) for their F-series trucks, particularly the F-250, F-350, F-450, F-550, and F-650, the Econoline Vans, and the Excursion SUV , as well as the LCF (low cab forward) diesel trucks.  The changes that Ford made in the 2003 powerstroke diesel engine in June of 2003 were tremendous, and some owners of Ford diesel trucks would say that the pre-change 7.3 Liter 2003 powerstroke diesel engine is in no way similar to the post-change 6.0 liter 2003 powerstroke diesel engine.  

2003 Powerstroke Diesel

Most of these changes to the 2003 powerstroke diesel engine made the engine more complex, more difficult to service, and more risky to modify or add after-market parts to.  These changes to the 2003 powerstroke diesel engine reduced the emissions drastically.  However, most 2003 powerstroke diesel truck owners would far prefer owning a 2003 powerstroke diesel truck equipped with the 7.3 Liter 2003 powerstroke diesel engine rather than the 6.0 Liter engine that Ford began using in its power stroke series after June of 2003.  

2003 Powerstroke 6.0 Liter Diesel

The 6.0 Liter diesel engines manufactured for later model years like the 2005, 2006, and 2007 diesel trucks are actually powerful engines with good towing capacity, in some cases, depending on after-market tuning, more powerful and have better towing capacity than the 7.3 liter diesel engines.  

2003 6.0L Powerstroke

However, the 6.0 Liter 2003 powerstroke diesel engines are widely disliked by diesel truck fans and owners.  These post-change 2003 powerstroke diesel engines are widely known for having a number of different major catastrophic engine and exhaust problems.  The EGR (exhuast gas recirculation) valves on the 6.0 liter 2003 powerstroke are extremely vulnerable to "coking" (becoming choked by carbon buildup), which can cause loss of power, which is unacceptable to diesel truck owners who use their trucks for towing heavy equipment and items like boats, lawnmowers, horse trailers, and machinery.  

6.0L VGT 2003 Powerstroke

The VGT (variable geometry turbocharger) on the 6.0 liter 2003 powerstroke is also known to be prone to sticking, due to problems with the solenoid on the actuator on the VGT.  When the solenoid stops working the actuator can't perform the job of opening and closing the vanes of the VGT, which can cause loss of power and even more troublesome problems for owners of the 6.0 liter 2003 powerstroke diesel trucks.  

6.0L 2003 Powerstroke Buyback

Owners of these 6.0 liter 2003 powerstroke diesel trucks in many cases sold their trucks very soon after buying them new from Ford dealers, and sometimes even sold their trucks directly back to the manufacturer through a buyback program designed by the Ford manufacturer to preserve those customers' loyalty.  Many of these 6.0 liter 2003 powerstroke diesel truck owners even switched brands to other manufacturers due to their extreme dissatisfaction with these unreliable trucks.