No one can accuse the engineers who designed the 6.0L Power Stroke® of not being bold; this engine was revolutionary in many respects. It offered exceptional power, lightning-quick turbo response and surprisingly good fuel economy. Unfortunately, it also presented early owners with a variety of reliability issues, particularly in true "work truck" applications, where heavier loads and increased combustion pressures and temperatures pushed the engine beyond its capabilities.
The good news is that, with the enhanced component designs developed in recent years, and – most important – proven new Fel-Pro® PermaTorque® MLS head gaskets, engine rebuilders and truck owners can be confident that the 6.0L Power Stroke will provide the reliability that was expected upon its introduction a decade ago. The following are some common issues that have been reported in the field:
Keep EGR Valves Clean; Watch the Cooler
Carbon contamination of the EGR valves (see Fig. 1) is one of the most common issues encountered on this engine. Once a valve is clogged, it can stick in the open position, causing a noticeable drop in power. The same contamination issue can affect the EGR cooler, leading to more serious consequences. These coolers are also prone to leakage, introducing coolant into the exhaust stream.
As noted above, this engine provides excellent turbo response…when everything is operating correctly. This is made possible by a "variable geometry turbo" design utilizing vanes (Fig. 2) to continually adjust the volume of the turbo housing. Keep these vanes clean of soot, either by removing and cleaning the turbo unit or, better yet, by periodically running the engine at full throttle.
The fuel injection control module, located on the driver’s-side valve cover, is reportedly sensitive to heat and vibration, both of which are in ample supply in this engine compartment. Many techs swear by the quality and value of units that have been professionally rebuilt (Fig. 3)…as long as they come with a warranty.
Yes, the obvious source of a coolant leak is a blown head gasket, which, in this engine, has happened with great frequency for many owners over the past decade. But don’t overlook the easy causes – one is a cracked degas bottle (Fig. 4).
Consider a Stud Kit
New Fel-Pro PermaTorque MLS head gaskets and T-T-Y head bolts (important: never, ever re-use T-T-Y bolts) will provide excellent reliability in this engine. In cases when power-adding modi.cations have been made, consider swapping out conventional head bolts with a highquality aftermarket stud kit (Fig. 5). This will signi.cantly increase clamp load and sealing strength in extreme conditions. John Gurnig runs the Fel-Pro Field Test Garage in Skokie, Ill.