6.0L Power Stroke Engine Upgrades

Upgrading problematic components and systems of the 6.0L Power Stroke can help improve engine longevity and reliability. These upgrades are not necessarily required for a stock 6.0L Power Stroke, but should be considered if you've got an itch to modify your engine with performance enhancers. For stock engines, the combination of these upgrades will greatly improve reliability, durability, and longevity.

EGR Cooler

Exhaust gases flowing into the EGR circuit are cooled by engine coolant in the EGR cooler. There are several methods of failure for the EGR cooler on a 6.0L Power Stroke, but many can be attributed to an EGR valve that becomes stuck in the closed position. When this happens, exhaust gases cannot travel through the cooler, raising the temperature and cooking the engine coolant. At these higher temperatures, the EGR cooler is prone to developing cracks.

EGR coolers can also clog when the internal heat exchanger collects excessive soot. A square EGR cooler was introduced for the 2004 model year and used until the engine's retirement, while a round cooler was used for the 2003 and early 2004 (2003 engine) model year. Although once touted as an improvement, the square coolers proved far more susceptible to failure than the early round coolers due to greater stress concentration points at the squared edges.

When a failure occurs, engine coolant typically leaks into the exhaust stream coming through the EGR cooler. An EGR cooler leak can be detected early on by frequent (every oil change) inspection of the EGR valve - white, crystalline build up on the EGR valve is indicative of coolant leaking into the EGR cooler.

Stainless steel 6.0 Power Stroke EGR cooler

Upgraded stainless steel EGR cooler for a 6.0L Power Stroke diesel

There many aftermarket EGR coolers available that address the shortcomings of the factory unit. Improved materials, construction, and larger heat exchanger passages result in a much more reliable system.

Turbocharger Oil Drain Tube

The turbocharger drain tube on 2003 to 2006 model year Power Stroke's is a "kinked" design, whereas a mandrel bent oil drain was introduced for the 6.0's final production year. The 2007 model year drain tube is favorable due to its smooth transitions, which are said to increase the flowrate of engine oil through the turbocharger by not "backing up".

Consider a garden hose that is kinked vs one that is not - water moves freely and at a greater rate than that of the kinked hose; the same concept can be applied with the turbo drain tube. Oil not only keeps the turbocharger bearings lubricated, but it also helps remove heat. Therefore, the greater flow of oil helps dissipate heat from the bearing assembly of the turbocharger. 2007 model drain tubes are compatible with any earlier 6.0 Power Stroke diesel. This is not an upgrade that makes any noticeable difference in engine operation, but will likely extend the life of your turbo.

6.0 Power Stroke upgraded turbo oil drain tube

Updated 2007 model year turbo oil drain tube for the 6.0L Power Stroke (left)
Note the smooth transitions and overall larger diameter

Fuel Injection Control Module (FICM)

The fuel injection control module, or simply FICM controls the firing of each individual fuel injector. It is commanded by the PCM to provide 48 volts (ideally) to an injector solenoid when that solenoid needs to be fired. The most prominent problem with the FICM is that it is located on the valve cover of the engine. While it's easy to get to, engine heat and vibration have a tendency to take their toll on the FICM. As a FICM begins to fail or operate out of spec, the output voltage decreases such that injectors will not fire properly.

Symptoms of a failing or failed FICM include hard start, no start, rough start, rough idle, low power, and related concerns. Consider replacing failed or faulty FICMs with an aftermarket alternative, preferably with a lifetime warranty. There are many manufacturers and re-builders who have a great understanding of the science behind FICM failures and build (or rebuild) units with much greater resilience. For information on FICM related problems, see: FICM troubleshooting and replacement information

Replacing TTY Head Bolts with Head Studs

The 6.0L Power Stroke is factory equipped with torque-to-yield (TTY) head bolts. TTY head bolts can be found in various OEM applications and one could argue that nothing is inherently wrong with employing such fasteners. During initial installation, these bolts are stretched beyond their yield strength such that they experience plastic deformation. It is for this reason that all TTY fasteners are designed for one time use and cannot be reused once they have been torqued to specification.

In 6.0L Power Stroke applications, the TTY head bolts are prone to stretching beyond their limits, resulting in head gasket leaks and even significant failures. There are many theories as to the root cause, including creep, fatigue, and heat induced failure modes. The problem is significantly more prominent in modified engines where higher cylinder pressures push the design limits of the factory head bolts. Ford Motor Company offers remanufactured 6.0L Power Stroke engines available with aftermarket head studs, acknowledging the breadth of this problem.

The solution is to replace the TTY head bolts with head studs, which provide a more evenly distributed clamping force. Head studs are available with impressive material properties that are far superior to the factory head bolts. Additionally, they are torqued within their yield strength limits and thus the deformation they experience is elastic, allowing them to be reused and providing addition defense against excessive stretching.

Head studs installed on a Power Stroke diesel

Head studs clamping the cylinder head on a Power Stroke diesel

ARP head studs (ARP 250-4202) are by far the most popular product distributed to 6.0L Power Stroke owners, although there are alternatives. There is nothing inherently wrong with the factory Ford head gaskets; Ford KC3Z-6051-A for 2003 to 2005 model year engines, KC3Z-6051-B for 2006 to 2007 engines. Installing head studs requires that the head gaskets be replaced.

Engine Oil Cooler

The oil cooler on the 6.0L Power Stroke has a tendency to clog and fail, often resulting in oil contamination of the cooling system. Since the lube oil system operates at a higher pressure than the cooling system, engine oil has a significantly higher propensity to leak into the cooling system than coolant into the lube oil supply. The oil cooler is essentially comprised of layers of thin heat exchangers stacked atop one another as identified in the cutaway view below.

6.0 Power Stroke clogged EGR cooler cutaway view

Cutaway view of a clogged oil cooler on a 6.0L Power Stroke

It is quite easy to distinguish the oil and coolant passages due to the clear build up of particulates in the cooling system circuit of the oil cooler. This is caused by silica in the engine coolant falling out of suspension and collecting to form larger particles that accumulate in the oil cooler passages, slowing and eventually clogging the heat exchanger.

The solution is to convert to a silica free extended life engine coolant (recommend Fleetguard ES COMPLEAT OAT ELC CC36073) and replace the oil cooler. We've found little need for aftermarket coolers as there is nothing inherently wrong with the OEM unit, but this problem will repeat itself so long as an engine coolant with silica compounds (which includes the factory Motorcraft Gold) is circulating through the system.

Installing a Bypass Oil Filtration Unit

A bypass oil filter adds an extra layer of protection against oil contamination. Particulates in the engine oil is an inherent problem for diesel engines, and while additional filtration is not necessarily required, it's a wise investment that may prolong the life of the 6 liters injection system and turbocharger. Since the system uses highly pressurized engine oil, HEUI injectors are sensitive to dirty oil; a bypass filter virtually eliminates these concerns.

Installing a Bypass Engine Coolant Filtration Unit

EGR and oil cooler failures often result from particulate matter in the engine coolant. Coolant passages in the heat exchanger can clog over time, reducing their effectiveness and increasing the chance of compounding problems. A coolant filter keeps particulates out of the cooling system, and isn't a bad investment if you plan on racking up some miles on your 6.0.

Preventative Maintenance for the 6.0 Power Stroke Diesel

Many of the 6.0L Power Stroke's "problems" can be prevented, or at the very least delayed by preventative maintenance that goes above and beyond the OEM recommended service procedures.

Clean the EGR Valve at Oil Change Intervals

Cleaning the EGR cooler at oil change intervals not only allows the EGR system to be inspected, but it also helps prevent EGR valve and cooler clogging conditions. The EGR valve is quite easy to remove and the gasket kit is quite inexpensive. See EGR valve cleaning procedures for additional information.

6.0 Power Stroke EGR valve

Dirty, soot impacted EGR valve versus a new, clean EGR valve

Replace Fuel Filters Every Other Oil Change

Diesel fuel systems are highly sensitive to contamination and diesel fuel is largely susceptible to water intrusion. In order to extend the service life of fuel injectors, we recommend changing both fuel filters and draining the fuel-water separator at every other oil change. If water is commonly found in the drained fuel, the source of fuel contamination should be sought and addressed.

Avoid Biodiesel Blends

As modern vehicles have adopted B20 biodiesel (20% biodiesel, 80% conventional diesel fuel) as an acceptable fuel, biodiesel blends are invading fuel stations across the United States. While using light B5 blends (5% biodiesel, 95% conventional diesel fuel) shouldn't be a cause for concern, much higher blends are being slipped into refueling stations under misleading labels such as "Renewable" diesel, which are often as high as 95% biodiesel and only 5% conventional diesel.

Interestingly, there isn't a vehicle sold by a domestic automaker that is certified for biodiesel fuels in excess of a B20 blend, and yet these highly concentrated biodiesel fuels are becoming more-and-more common. While running a tank of biodiesel through the engine isn't likely cause any immediate problems, it has an extremely short shelf life (often less than 3 months). When it "spoils", it leaves an adhesive-like residue on anything it touches, ultimately clogging the fuel system. Stick to conventional diesel fuel as prescribed by the vehicle and engine manufacturers to avoid fuel system component failures.

Use Fuel Additives Often

You should be using a fuel additive. It doesn't matter if you own a 1980's IDI or a brand new 6.7L Power Stroke, the quality of diesel fuel in the United States varies considerably between acceptable and terrible. Furthermore, ULSD lacks many of the beneficial properties provided by the previous low sulfur diesel specification. A fuel additive can provide benefits that include lower particulate emission (lower sensitivity to VGT vane and EGR valve clogging), fuel system protection, increased fuel economy, protection against fuel contamination, and prolonged diesel fuel storage life (particularly important for trucks that are driven infrequently). Ford even recommends that you use their fuel additive with every tank!

While there is nothing wrong with the OEM additive, there are many high quality, more diverse fuel additives available. Give Opti-Lube XDP or Archoil AR6200 a try. Both have received high remarks in independent tests. Follow the manufacturers directions to ensure a proper dosage - more is not better. Don't be alarmed by the high cost of an additive as the concentrate tends to go a long way.

Consider an Engine Oil Additive

In addition to using a synthetic motor oil, you should be using a supplementary oil additive to combat stiction. Do not use just any oil additive, it needs to be specifically designed for the HEUI injection system. Stiction occurs when engine oil breaks down under intense mechanical pressure in the injector valve, coating the spool valve with a carbon build up typically described as a varnish.

Over time, this effect has a tendency to cause an injector to misfire. We stand by Archoil AR9100 friction modifier (16 oz is needed per oil change), which has worked wonders eliminating misfire related problems and DTCs in both the 7.3L and 6.0L Power Strokes. If you find yourself struggling to justify the additional cost of an oil additive, we suggest using it at a minimum of every other oil change.

Avoid Performance Enhancers

You may not want to hear it, but the most reliable vehicle you can own is one that is sans aftermarket performance products. As much as we love the extra power and torque that this engine platform is capable of making, such products risk engine reliability and longevity. Maintained properly and treated well, the 6.0L Power Stroke will survive several hundred thousands of miles at stock power levels, just as it was designed to do.

Summary & Key Points

• The 6.0L Power Stroke's inherent flaws center around the EGR system, TTY head bolts, engine coolant type, and the sensitivity of many of its electronic components

• Some of the Power Stroke's common problems can be addressed with aftermarket solutions, while others can be prevented with addition maintenance

• Aftermarket performance products may compromise the reliability of the 6.0L Power Stroke by putting addition strain and stress on otherwise sensitive systems