This dependability has made the Navistar-Ford engine series an extremely popular choice both as a new and as a used engine in a wide variety of trucks and other types of vehicles. Nevertheless, there has been an exception to the rule, the 6.0L engine introduced in 2003 as a replacement for the 7.3L. Not only was this diesel engine unable to live up to those lofty Power Stroke standards, it earned one of the worst reputations of all time among all engines in the diesel industry.
Much of that reputation was underserved. Nevertheless, it was so prevalent that just two years after Ford had introduced the 6.0L, they were already preparing to replace it with the all-new 6.4L Power Stroke. By the 2007 model year, that transition was nearly complete. Ford did, however, continue to use the ’07 engine in the full-size vans of the E-series through the 2009 calendar year. When the last E-series van sold, Ford officially retired the 6.0L diesel engine, but of course, they will continue to support it for years to come.
The debacle with this engine has created some opportunity for the consumer who would buy the 6.0L as a used engine. There are many aggressive deals available, and the engine is not nearly as bad as the reputation suggests it is. In fact, the 6.0L met all emission standards and it survived stringent testing during both the research and development stages. In other words, the engine should not be problematic in its stock form, which means that most issues arise in application and modification.
The statistics support this. According to the experts at Diesel Tech, this engine rarely experiences major failure when operating at stock power levels. Therefore, there’s tremendous value here for the consumer who is aware of the common issues and the steps needed to counter them. Let’s examine the most frequent issues, which should help you decide if this used engine makes sense for your situation.
The most common problems that this engine series succumbs to, and the ones you’re most likely to experience from a used engine, occur with the EGR. In one common case, the EGR cooler simply fails because of blockage that occurs due to its restrictive rectangular design, which is inappropriate for the application. In the other common case, the EGR valve sticks due to carbon buildup, which occurs during engine idle because of low combustion efficiency at those speeds.
It is important to note that these common problems with the EGR system play a strong role in the head gasket failure for which this engine is so infamous. Therefore, it is vital when purchasing this used engine to ensure that it already has an upgraded EGR cooler installed, or that you factor in the additional expense of one, and include this upgrade during the installation of the engine or even install it yourself after the fact. EGR upgrade kits are not difficult to install, but the process is time-consuming and requires a professional set of tools.
Another factor that plays a role in head gasket failure on all 2003-07 engines are the head bolts that Ford used. These are not generally an issue with the engine in stock form, but many owners will simply have them upgraded if they ever need to replace the head gasket. However, upgrading the head studs is much more of a necessity for a modified engine because the factory bolts displace load unevenly, and problems will manifest quickly at anything above stock power output. Therefore, this is an important consideration due to the expense of the upgrade if you’re dealing with a modified engine or plan to modify it yourself.
Turbo failure is another common problem, and in the 2003-05 models, this occurs because of the restrictive oil drain tube that Ford used. The good news here is that this is a relatively inexpensive upgrade. Ford attempted to rectify this problem for the 2006 model, but they actually worsened it because the new system lacked an internal turbo groove. Ford corrected this problem properly for the 2007 model, and the 2007 version is the most reliable turbo system ever made for this engine. When buying a 2006 engine, it is best to seek one that already has the 2007 turbo unit in place because that upgrade is inevitable.
In addition, when Ford launched this engine, it included an improperly calibrated ICP sensor. All engines from 2004 on have the correct ICP sensor. For owners of a 2003 model, it’s important to recognize the issue because many inexperienced owners will spot oil beneath the truck and assume the worst. However, if the oil is leaking beneath the turbo, a bad ICP sensor is generally the culprit, and replacing it will correct the issue. This is an inexpensive part, and a simple installation, and you should expect this part upgraded as part of the installation process, if not already installed.
The bottom line is that this engine, despite its dreadful reputation, can be quite durable and a fantastic value. When buying used, there are a couple of keys to a successful purchase. First, buy through a respectable dealer. You should have free, thorough access to the engine history as well as a minimum one-year warranty with the option to upgrade to two. Second, choose your mechanic carefully. Especially with an engine like this one, it is vital that the mechanic adheres to and makes the adjustments according to all of the technical service bulletins during the install.