THE KEY DIFFERENCES BETWEEN EARLY AND LATE MODEL ’03-’07 POWER STROKES

 TEXT AND PHOTOS BY MIKE MCGLOTHLIN

RUNNING ’03 & ’04 MODEL YEAR CHANGES

Most folks are aware that there were a boatload of subtle updates made between the ’03 and later versions of the 6.0L Power Stroke, but many don’t know that the pistons were different. Almost exclusively driven by emissions standards, ’04 model engines—beginning with serial number 6155637 in Indianapolis and serial number 0094580 at the Huntsville, Alabama plant—featured a crown with a smoother radius (right). This was done to increase the efficiency of the combustion event (namely to clean up particulate matter emissions). The piston’s skirt and ring lands were unchanged, as was its overall diameter. The beginning production date for’04 engines equipped with the updated pistons was September 29, 2003.

If you own a 6.0L Power Stroke, you have an engine that is at least 14 years old. And if you haven’t yet had to venture under the hood, you soon will. Contrary to what many outsiders believe, catastrophic engine failures are few and far between with the 6.0L. However, intermittent component failures are inevitable and can sideline you and your truck if you aren’t prepared, or aware of this engine’s common quirks. It’s equally important to mention that as these trucks age and become even more affordable to purchase on the used market, more and more owners perform their own repairs rather than take them to a dealership or an independent shop. It’s just the nature of the beast.

In the following pages, we’ll spell out the primary differences between early and late engines, as well as the changes that were implemented beginning in ’05. Some of the distinctions are obvious (the 10-blade ’03 VGT vs. the quieter 13-blade turbo on ’04-‘07s), while others (such as different cams, pistons, glow plugs, and water pumps) are more obscure. By knowing exactly which version of the 6.0L Power Stroke you’re dealing with, it’s our hope that the information contained here will remove all guesswork from your required repairs.

As a result of the piston changes that were integrated into the ’04 engines, shorter glow plugs were used. The glow plugs are exactly 1.2mm shorter than the versions employed in ’03 engines, so in order to avoid potentially catastrophic engine carnage through piston-to-glow plug contact make sure you don’t install longer, ’03 glow plugs in an ’04 or newer 6.0L. As for the glow plug module, beginning in ’04 its bracket was altered in order to accept the new positioning of the relocated ICP sensor (more on the ICP sensor in a bit).