As the diesel fuel begins to dilute the oil, these feet lose their lubrication and start getting chewed apart to the point where the rocker itself will start scraping the bridge. These small feet on the tip of the rocker need engine oil to keep everything moving and sliding correctly. The rocker has a small foot on the tip which contacts your valve bridge, this 'foot' allows the rocker to push down two valves simultaneously. The first signs of this oil dilution were in the valve train where the rocker tips would start to wear down so quickly, they would begin to stick and sometimes break. With the DPF & EGR systems still intact, the engine was pouring fuel through the cylinders to make enough heat to burn the DPF clean, we found this excess fuel was beginning to dilute the truck's oil with diesel fuel. We started to notice a pattern with the condition of the truck and the issues they were having. As time went on, we started to see these trucks more and more for engine work and started to learn a few things. It wasn't long until we started to see the odd engine failure here and there, however, we just chalked it up to all the added power we were throwing at them.
The beauty of the 6.4L Powerstroke was how little work you needed to do to turn a boring stock truck into a track monster. With a fuel system and transmission that could handle all the added power, all you need is an exhaust and a tuner and trucks were putting down 500+ horsepower to the wheels and they were getting 20mpg while doing it. At the time, diesel motorsports were becoming quite popular and the 6.4L Super Duty was here to party. They sucked back fuel, but, they made decent power, however, when the emissions systems were removed, the trucks turned in complete animals. This was the early stages of the DPF system, this was before DEF fluid was used and the trucks had to rely on the heat of the engine to burn out the catalysts. With the introduction of the first round of the DPF and the increasingly intense EGR systems, these trucks started to plug up quick. Unfortunately, the 6.4L was introduced into the market at the same time as emissions laws became much more strict and manufacturers had to start engineering their trucks to a much higher standard. Ford was finally in-line with their competition! This meant no more tough starting, rough running, high-pressure oil leaking fun that Ford guys had gotten accustomed to over the last 14 years! Finally, Ford fans didn't have to drive something that was the butt of every diesel joke out there. For the first time, since the old IDI engine, the fuel system was built on a common rail design rather than the HEUI design (Hydraulic Electronic Unit Injector). When the 6.4L Super Duty was first introduced, it was nothing short of a game-changer for Ford owners. The F-250 through F-550 came out the gate boasting a stout 6.4L Powerstroke engine built by International. In 2007, halfway through the year, Ford Motor Company introduced its latest Super Duty F-Series trucks.