The 6.0L Powerstroke Diesel

by Rob Gaskell, Jr. and Rob Gaskell, Sr.

The 6.0L Powerstroke was released in the model year 2003 as a replacement for Ford's 7.3L Powerstroke and uses an updated version of the HEUI fuel system found on the 7.3L, as well as many new technologies. The 6.0L PSD was a response to new, more strict emissions standards for light-duty diesel trucks in North America. Additionally, the 6.0L was an attempt to compete with the higher-horsepower diesels in the light truck market, not a surprising concern for the makers of a brand name which gets its name from the power stroke of an internal combustion engine, or the downward stroke of the piston which is caused by combustion and which provides the power to the engine.

Despite the efforts of Ford and International/Navistar, the 6 Liter (Litre) has shown significant reliability issues. These problems can be very costly to repair, leading many owners to consider replacing their 6.0L-powered Super Duty trucks with a different make. This is generally not the most economical option, since the original purchase price of these trucks is very high, and has depreciated significantly due to the reliability concerns surrounding the engine. By proactively upgrading, performing maintenance beyond manufacturer specifications and responding quickly to trouble symptoms, the 6.0L Powerstroke can be made very reliable at a cost which is more economical than taking a loss on the truck and gaining a new truck payment.

The Operation

The 6.0L Powerstroke uses the Siemens-designed HEUI (Hydraulic Electronic Unit Injection) fuel system, an updated version of that used on the 7.3L Powerstroke. The 6.0L also incorporates many technologies not found on its predecessor. These technologies include a Variable Geometry Turbocharger (VGT), and an Exhaust Gas Recirculation (EGR) system. This section provides a brief overview of the operation of the 6.0L and its sub-systems. For problems associated with these and other systems, as well as solutions to these problems, read the Issues and Answers sections below.

Fuel System Operation

The 6.0L HEUI fuel system uses 4 main components, including a high-pressure oil pump (HPOP), a fuel lift pump, a Fuel Injection Control Module (FICM), and 8 hydraulic-electronic fuel injectors. For more on HEUI injection system operation, see our Powerstroke Diesel Injection article.

The HPOP pressurizes engine oil and delivers it to oil galleries mounted on top of the fuel injectors, under the valve covers. The HPOP oil pressure is controlled by an injection control pressure regulator (IPR), which is installed in the HPOP cover located at the rear of the engine valley, under the VGT. A signal is sent to the IPR, forcing it to open or close, thereby regulating the volume and the pressure of the oil delivered to the oil galleries and injectors.

The fuel lift pump is mounted to the frame under the left-hand side of the cab. This pump delivers low-pressure fuel to the fuel galleries in the cylinder heads, through two fuel filters. The fuel galleries are cast into the iron cylinder heads and are open to the fuel ports on the fuel injectors. This pump is part of the HFCM, horizontally mounted fuel conditioning module. This module contains a fuel lift pump, fuel heater, water in fuel sensor on early models, a filter separator element and a manifold assembly.

The Fuel Injection Control Module, or FICM, is an electronic module which provides a 48 Volt control signal to a pair of 20 amp coils on the HEUI fuel injectors and works in conjunction with the Powertrain Control Module, or PCM, in operating the 6.0L fuel injection system.

The fuel injectors on the 6.0L have a port on top for high-pressure engine oil, as well as fuel ports located on the side, below the oil section of the fuel injector. A constant supply of fuel is allowed to enter the fuel injector, and high-pressure engine oil is allowed to enter the fuel injector through an electrically operated valve called a spool valve. The amount of fuel delivered by the fuel injector is determined by the fuel injector pulse width, which describes the amount of time the spool valve is open, as well as the injection control pressure, or the oil pressure which is controlled by the IPR. The high-pressure oil is used to pressurize fuel within the injector at a 7:1 ratio, which forces open the pintle at the tip of the fuel injector, allowing fuel to enter the combustion chamber. The amplification of the oil pressure equates to a higher injection pressure and injector on time increases fuel quantity. Higher injection pressures are needed for better atomization of the fuel and to improve combustion at higher cylinder pressures encountered under heavy demand. It is important to note the minimum fuel filter replacement requirement is 15,000 miles. During a filter change, one should inspect the HFCM for debris by pulling the drain plug on the housing and inspect for any debris that can be seen in the fuel, inside the drain hole or filter housing. If debris is found the HFCM should be removed for cleaning. There is a manifold on the HFCM that is held in place by four screws. This should be removed and the area cleared of any debris while cleaning. A gasket is readily available from Ford. A build-up of debris in this area will cause a restriction in the fuel supply system. This will cause low power and will result in injector failure.

It is very common for us to find this condition. By the time we see this, it is usually too late to save injectors due to the damage already done. Injector failure generally starts on the right injector bank do to the extra distance fuel must travel as opposed to the left injector bank. If this condition has been present for any length of time, injector failure is almost certain especially on trucks which regularly haul heavy loads or where spirited driving is the norm. All of these failures are preventable. A failure due to some sort of flaw in the injector is extremely rare. Even when an injector loses a tip into the combustion chamber and destroys a piston and takes out a cylinder block, in all probability at some point the injector was damaged due to a lack of fuel or some other contributing factor such as sustained high combustion temperatures incurred while under heavy load or a power adding device.

Variable Geometry Turbo Operation

The 6.0L VGT uses a low-pressure oil-operated actuator to drive the turbocharger turbine vanes through a range of positions, thereby controlling turbocharger speed as well as exhaust backpressure and intake manifold boost pressure. The VGT is also used in conjunction with the EGR valve to control EGR system operation. The VGT oil actuator receives a signal which delivers oil at differing ratios to a hydraulic piston. The difference in oil pressure on each side of the piston drives the piston in opposite directions, allowing the actuator to move the vanes in either direction or hold them in any given position by varying actuator duty cycle. VGT position feedback is supplied to the PCM through the use of a plunger on the end of the actuator which makes contact with a cam lobe attached to the shaft which drives a pin that drives the unison ring as well.

Exhaust Gas Recirculation System Operation

The EGR system on the 6.0L uses 3 main components, including an EGR valve, EGR cooler, as well as the VGT. The EGR system is designed to lower combustion temperatures, thereby reducing the production of oxides of nitrogen, which contribute to smog and acid rain. For more on this, read our Exhaust Emissions article.

The EGR valve is mounted to the top of the intake manifold, and controls the flow of exhaust gases into the intake manifold. These exhaust gases must flow through the EGR cooler, which is a coolant-to-exhaust cooler which is designed to lower the temperature of the exhaust gases, thereby increasing the EGR system's ability to lower combustion temperatures. The VGT enables the flow of these exhaust gases by increasing exhaust backpressure, which must be higher than intake manifold boost pressure in order for exhaust gases to flow into the intake. EGR flow is then operated by a combination of VGT exhaust and boost pressure control, as well as EGR valve position.

Engine Oil Cooler Operation

The 6.0L uses a coolant-to-oil engine oil cooler, which is mounted at the front of the engine valley below the oil filter housing. Small passages inside the heat exchanger portion of the engine oil cooler flow coolant and engine oil, allowing heat from the engine oil to be transferred into the coolant. Coolant then exits the engine oil cooler, and enters the EGR cooler. Proper cooling of the engine oil on the 6.0L is critical, since this oil is used to operate the fuel injectors, as well as cool internal engine components which engine coolant cannot reach. For more on engine oil cooler operation, see the Issues and Answers sections below.

The Issues

We provide you with proven solutions for all of the issues which plague the 6.0L Powerstroke diesel.

There are several reliability issues with the 6.0L Powerstroke. The most significant of these include EGR and engine oil cooler failure, as well as head gasket failure. Other common reliability issues incude variable-geometry turbo (VGT) issues, fuel-injection control module (FICM) failure, and fuel injection system failures, among others. It is interesting to note that the 6.0L engine has proven to be significantly more reliable in it's original application, powering medium-duty International trucks. This can be attributed to significantly lower-horsepower tunes, as well as a more open engine compartment which allows for better airflow through the radiator and better heat dissipation from the engine. The remainder of this section covers the common issues in the Ford 6.0L application.

Engine Oil Cooler Issues

The two most common failures of this cooler include clogging of the coolant passages due to deposits, which form as a result of contaminated or unmaintained coolant, and internal leakage between the coolant and oil passages causing a mixture of fluid. The first of these issues, clogging of the coolant passages, results in higher than normal engine oil temperatures. The best way to prevent damage due to unnoticed engine oil cooler clogging is to have the vehicle maintained by a qualified repair facility that inspects engine oil operating temperatures regularly and can recognize the signs of oil cooler trouble, as well as performing a cooling system flush approximately every two years, depending on usage.

It is very important that the Trucks cooling system is in proper operating condition. This system includes the radiator, EGR cooler, Oil cooler, degas bottle, degas or radiator cap, hoses, coolant and oil temperature sensors and cooling fan. Any coolant leaks should be located and repaired right away. Ideally it is a great idea to have gauges or a display to monitor coolant, oil and exhaust temperatures, especially if you tow on a regular basis. Any deficiencies in the cooling system will lead to head gasket failure.

This failure can lead to premature engine wear, fuel injector failure and localized overheating of engine components. Engine oil in the 6.0Liter is used not only as a lubricant but high-pressure engine oil is also used to operate the fuel injectors, as explained in our Powerstroke Diesel Injection article. Engine oil is also used as a method of cooling engine components such as pistons, adding to the threat of localized overheating. This localized overheating is typically not indicated by the engine coolant temperature gauge and may go unnoticed by the driver, increasing the importance of proper maintenance by a qualified facility. Note: The latest operating system strategies have added enhanced cooling system monitoring which monitor oil temperatures and will now reflect an oil overheat condition through the coolant temperature gauge, set a DTC, and illuminate the amber wrench symbol in the instrument cluster. This shows the importance off keeping your trucks operating system up to date.

The second of the common engine oil cooler failures, leakage between the coolant and oil passages, is more serious and can lead to severe engine damage. The best way to prevent this failure is to eliminate the stock engine oil cooler and replace it with a Bulletproof Engine Oil Cooler, which is an air-to-oil rather than coolant-to-oil cooler.

The most apparent symptom of this type of leakage is usually the presence of oil in the coolant expansion bottle, as well as a milky appearance and consistency of engine oil or coolant due to mixing of the fluids. Since engine oil is under greater pressure than engine coolant, more oil typically enters the cooling system than coolant enters the engine crankcase. This oil contamination can cause sludging in the cooling system, reducing cooling to critical engine parts, causing localized overheating and premature failure of these parts. If left unnoticed, it can also reduce engine oil level and cause engine failure. Also, if enough coolant does enter the crankcase, it can contaminate and dilute the engine oil, removing its ability to lubricate engine components, leading to severe damage such as camshaft and crankshaft bearing failures, valve train damage and most notably, injector spool valve failure.

EGR Cooler Issues

The 6.0L Powerstroke EGR cooler is mounted below the intake manifold on the right-hand side of the engine, and is prone to rupturing, allowing coolant to leak into the exhaust system. The best way to prevent damage due to EGR cooler failure is to properly maintain or eliminate the stock engine oil cooler, as explained above, as well as to upgrade the EGR system with a Bulletproof EGR Cooler, which to date has never had a reported failure, and features a lifetime warranty.

Common symptoms include steam from the exhaust while driving, as well as coolant loss with no evidence of external leakage. These symptoms may also be a sign of blown head gaskets, and this condition should always be tested for, even if the EGR cooler is known to be leaking. The EGR cooler uses engine coolant to cool exhaust gases which are reintroduced into the engine's intake to cool combustion temperatures and reduce nitrous oxide emissions. The EGR cooler commonly fails due to overheating and boiling of the coolant inside it, rupturing it and causing coolant to leak into the exhaust manifold. This overheating within the cooler is sometimes caused by low coolant flow to the cooler, since coolant must pass through the stock engine oil cooler before it is delivered to the EGR cooler. As the engine oil cooler begins to clog, the EGR cooler is starved for coolant. If the cooler leaks while the engine is not running, coolant can enter engine cylinders through open exhaust valves. Attempting to start the engine after coolant has entered a cylinder can lead to hydrolocking, where the incompressible coolant in the cylinder stops the engine from turning. The affected cylinder's connecting rod may bend as a result, requiring significant internal engine repairs or engine replacement to correct.

If you have this condition it is best to avoid starting the engine until the coolant has been cleared from the cylinders. This can sometimes be done by turning the engine over slowly by hand a few revolutions, but is best done by pulling the glow plugs and jumping the starter to blow the coolant from the cylinders. Coolant will generally only be in one or two of cylinders on the right hand bank , but during a hot soak, the water in the coolant mixture can condense in the entire up-pipe, and can enter the left bank as well. The VGT turbo should always be serviced during an EGR cooler repair. Coolant/water will pass through the VGT and cause corrosion of the unison ring and turbo vanes.

EGR Valve Issues

The 6.0L EGR system uses a electronic solenoid-operated EGR valve with a built-in position sensor. It is important to take care when cleaning your EGR valve. The position sensor uses a potentiometer which is very sensitive to solvents and other harsh cleaning agents such as brake or carb cleaner. There are two vent holes on the underside of the valve in which these cleaners can enter and damage the position sensor. The EGR system recirculates exhaust gases to cool combustion temperatures and reduce the production of oxides of nitrogen. Oxides of nitrogen produce brown smog and acid rain, as explained in our Exhaust Emissions article. The EGR valve is prone to occasional sticking due to carbon buildup, as well as failure of the position sensor. The best way to prevent problems with the EGR valve is to avoid excessive engine idling, and to take extreme care when cleaning the valve. The EGR system operates during engine idling, and the low exhaust back pressure present during engine idling means that EGR gases flow at relatively low speed through the EGR valve. This allows the carbon soot to deposit on the EGR valve, which may require periodic cleaning. If the EGR valve is to be cleaned, extreme care should be taken to avoid allowing cleaner or other liquids and debris to enter the EGR valve solenoid housing, as this can lead to failure of the position sensor located inside the top of the EGR valve assembly. Intake and EGR system deposits can also be exacerbated by oil residue as a result of excess cranckcase pressures, or a failed or over loaded cranckcase vent oil mist seperator. a small amount of oil present in the turbo compressor area or CAC tube connections is considered normal. These deposits in the intake system can cause reduced performance. There will generally be deposits on the intake ports and valves which can interfere with proper airflow into the cylinders either by interrupting, causing turbulence, or restricting airflow. As this platform ages and more miles and years are accumulated, this is becoming more common. Part of our cylinder head inspection which is performed during a head gasket repair is to clean these intake and valve deposits. There are methods to remove these deposits using a system specifically designed for this purpose as well.

Common symptoms of improper EGR valve operation can sometimes mirror those of improper VGT operation. When the EGR valve sticks open or is opened further than desired due to position sensor failure, boost pressure is allowed to escape from the intake manifold and enter the exhaust through the EGR cooler. EGR valve performance issues often lead 6.0L Powerstroke owners to install EGR delete kits. While removing the EGR system does eliminate the problems with the EGR valve, it is important to note some of the drawbacks of removing the EGR system, discussed in our EGR Delete Concerns article.

Turbocharger Issues

The 6.0L uses a Variable Geometry Turbo. This VGT is prone to sticking, which can happen over time due to normal carbon buildup inside the turbo, and can happen very rapidly if there are engine misfires or other fuel system problems. Excessive exhaust smoke, misfires or a lack of power should be address as soon as possible, since they may be signs of turbocharger or other problems which can lead to additional damage if left unaddressed. Carbon buildup in the VGT is usually repairable without replacement of the turbo, provided it is addressed early. Additionally, the turbo can become seriously damaged if there are significant engine misfires, or from the use of performance programmers which tend to increase exhaust gas temperatures beyond safe levels.

For more on turbocharger operation symptoms, see the EGR valve section below.

Head Gasket Failures

Head gasket failure, also known as "blown head gaskets," has proven to be an almost inevitable problem on the 6.0L Powerstroke, particularly on vehicles with performance tuners and those that tow heavy loads. The best way to prevent head gasket failure and damage to the cylinder heads is to perform an ARP Head Stud Installation preventively, rather than waiting for a serious problem to arise. When performed preventively, less material can be shaved from the surface of the cylinder heads generally, and there is less of a chance that cylinder heads will be damaged beyond repair due to head gasket leakage. Ford had revised the procedure for measuring a 6.0L cylinder head which proves what we've said all along, any erosion or low areas on the sealing surface of the cylinder head greatly increases the chances os a repeat head gasket failure. The new procedure is not to measure warpage, but to check for low spots on the surface which will eventually lead to future leakage. The 6.0L cylinder head is actually a very robust piece and it is not the overall lateral warpage which is of concern and effects sealing so much as the pitting which occurs and the bolt failure that happens over time due to failures and deficiencies in the cooling system. This pitting is a direct result of degraded coolant which has lost its rust inhibitors. The pitting occurs in areas where the coolant passes through ports between the cylinder head and block. There are areas around these coolant ports which are not sealed from each other. Coolant can over time enter these areas on both sides of the gasket and cause this pitting on the cylinder head and block deck sealing surfaces, though block deck surface pitting seems to less severe than cylinder head pitting and can usually be cleaned satisfactorily in most cases.

There has been quite a bit of controversy concerning the milling of the 6.0L cylinder heads. After milling many, many 6.0L cylinder heads over the past several years and not seeing one repeat failure or any valve train clearance issues, I would have to say it is a total crap shoot to not machine a pitted head surface. I have seen several repeat head gasket failures even with studs and new gaskets on cylinder heads in which milling was not performed. Most cylinder head pitting can be remove by milling .003 to .005 from it's surface. I personally do not feel comfortable with anything that would exceed .008 so I will recommend cylinder head replacement when measurements indicate this limit would be exceeded.

Common symptoms of head gasket failure include coolant residue on and around the coolant expansion bottle, and intermittent overheating under heavy load. Head gaskets on the 6.0L leak due to expansion, or stretching, of the stock cylinder head bolts. As the engine heats and cools, the cylinder heads, engine block, gaskets and bolts expand and contract. During periods of high localized heating, such as when pulling a hill under load, the expansion of the cylinder head bolts causes the clamping force they exert on the cylinder head gaskets to reduce to less than that of the force of engine combustion pressures, which breaks the seal between the surfaces. When this happens, combustion escapes from the cylinder head and begins to damage the surface of the cylinder head, engine block and gasket. Combustion pressure leaks into the cooling system, causing coolant to be expelled from the coolant pressure cap, and in the early stages will not cause coolant to enter the combustion chamber. In fact, a 6.0L in the early stages of head gasket failure will usually pass extended cooling system leak down tests. It is also very common for drivers who only tow with their 6.0L for recreation in summer to notice coolant loss and overheating during a summer trip, and experience no problems all winter until their next trip. This intermittent combustion leak is due to the higher-than-normal combustion pressures and temperatures present when towing. A couple of items to note is the degas or radiator cap, and the minimum coolant level. Most OEM caps I have tested which have a pressure rating of 16 lbs test at only 8 lbs or less. This could very well mean the majority of the Trucks out there have failed radiator caps. The cooling system was designed to hold a minimum of 12 to 18 lbs pressure. Lower pressures result in the boiling of coolant at a lower temperature than expected under this condition, since many of these trucks have degraded coolant, diluted mixtures and the cooling systems have been neglected, the boiling point of the coolant would be even lower. This is a critical point when considering the localized areas of overheating which can occur around the combustion chambers, Oil cooler and EGR cooler. This makes it important to test and replace the cap with an upgraded version specifically designed for the diesel application which is available from Ford. The new cap has a larger diameter spring in the pressure relief valve which is much more robust and less likely to fail in a short period of time.

We still find many trucks which do not have the revised coolant minimum level decal attached to the degas bottle. The revised minimum level has been reduced to 5/8" below the original minimum mark. This reduced level allows for more expansion room in the bottle and was thought to eliminate coolant venting. We have found in every case in which the cooling fan was functioning properly, the venting of coolant while under heavy engine load was a direct indication of a head gasket failure. Even in cases where the oil cooler was severely restricted and oil temps elevated.

Another issue we find from time to time is fuel in the cooling system. There are two things which can cause this, one is a failed and leaking injector cup, the other is a crack in the injector bore.

The injector cups and glow plug cup inserts are wet, meaning they are in direct contact with coolant. They can sometimes become damaged and leak causing fuel to enter the cooling system. Cracks in the injector bore are usually a result of an overheating condition. These cracks will allow fuel to enter the cooling system as well. An injector cup which is leaking can be replaced. There is no fix for a cracked injector bore, the cylinder head must be replaced.

Fuel Injection System Issues

A few fuel system failures are common to the 6Liter, such as fuel injector failure and high pressure oil system leaks. Fuel injector failures are commonly caused by improper installation of new or reinstallation of existing fuel injectors, as well as poor fuel quality and improper fuel filter maintenance. The best way to prevent fuel system problems is to maintain your engine oil and fuel filters, using only genuine Motorcraft fuel filters due to their exclusive patented features. Oil should be changed roughly every 4,000 to 5,000mi, and fuel filters should be changed at least every other oil change or at 15,000 miles minimum. The use of questionably-sourced biofuels and other low-quality fuels such as off-road diesel should also be strictly avoided. Biodiesels of more than 5% are not recommended for the 6.0L and can cause driveability concerns.

It is vital that fuel injectors receive a clean, water-free and constant supply of fuel, and that the high-pressure oil they receive is clean and of the proper viscosity. The most important reason to use Motorcraft fuel filters is the presence of an outer paper layer that is exclusive to the Motorcraft filter, which acts as an additional water barrier. It is also important to address any lack of power or rough idle issues, as this can be a sign of a fuel supply shortage. Fuel acts as a lubricant for the precision components within the fuel injector, and supply shortages can damage the injector due to operation without proper lubrication.

One of the flaws with the 6.0 liter fuel system is the way it is designed. If everything is working properly, it generally performs well however, it is possible to upgrade and improve injector performance and life. The stock fuel system is a dead end system, meaning fuel is sent into the fuel rail portion of the cylinder head where it dead ends. Any air trapped in the system on start up or while running can only be removed by passing through an injector causing a dry injection event. A dry injection event will eventually destroy injectors due to a lack of lubrication as stated earlier. There is a kit available from Ford which consists of a new regulator spring, a few sealing components to increase fuel pressure. At the very least, this should be installed. While this is an improvement we have found a better solution made by Driven Diesel. It is a regulated return fuel system. This system allows fuel to pass through the fuel rail section of the cylinder head before it is regulated and and the excess is passed into the return circuit. This means a constant relatively cool supply of fuel is available at the injector under all driving conditions. The benefits of this system far outweigh the cost in both performance improvement and injector life. the system has an adjustable regulator which can be set to a constant 60-70 PSI. We have found a stock fuel lift pump to be more than capable of suppling enough volume and pressure to ensure proper performance under all driving conditions with a stock or mildly tuned 6.0 liter. Low fuel pressure and lack of fuel within the injector cause the intensifier plunger to over-extend and can damage the injector and weaken the return spring. Not only does the fuel act as a lubricant, but it also provides a buffer or cushion for the intensifier plunger.

The 6.0L's Fuel Injection Control Module is prone to occasional failure, particularly. Many of these failures can be directly attributed to battery, charging system and connection issues. Any voltage drop in the supply to the FICM will cause overheating of components and eventual failure. Battery and charging system integrity are important to ensure longevity and proper FICM performance especially if you have the inductive heating flash. The inductive heating flash adds current draw on the system when active. This added current can cause heating of components and circuitry. I do not see any evidence that inductive heating shortens the life of the FICM unless there are deficiencies elsewhere in the electrical/power supply to FICM, in which case will also cause failure without inductive heating.

No matter what you might have heard about inductive heating and its possible effects on FICM durability, it works. It solves a high percentage of no start, hard start and poor acceleration when cold conditions and extends the service life of the injectors. Before inductive heating, the only way to solve this condition was to replace the injectors. As the spool valve and it's bore wear over time, the amount of oil that accumulates between the ends of the spool valve and coils increases. This oil when cold will latch onto the spool valve as the open and close coils activate to position the spool valve. This basically slows the movement of the spool valve and can cause a no start when cold, hard start and stall when cold and poor cold acceleration performance. Inductive heating was designed to rapidly heat this accumulated oil by adding current to the control coils which creates heat, allowing the spool valve to move freely as though engine oil was at operating temperature.

Powerstroke Diesel Injection

The high-pressure oil system on the 6.0L is also prone to leakage at fittings inside the engine, causing a no-start condition. Oil will leak from the high-pressure oil system back into the crankcase, and therefore this issue will not be evident based on visual inspection of the engine. There are upgraded high pressure oil system components available from Ford which solve most high pressure oil system leaks. It is amazing how many trucks we see, even 2007's that have the old style stand pipes and short plugs. If you want to improve any part of your 2004.5 to 2007 6.0 liter, this is the best place to start. A high pressure oil system leak can leave you stranded in the middle of nowhere at any time. The new and improved components have an added teflon back up washer installed behind the sealing O ring. I have not yet seen a repeat failure of these components since these parts have been available.

The Answers

Owners of the 6.0L Powerstroke often express a desire to replace their trucks with an earlier model Ford or another make, either due to a history of problems with their own truck, or because of worry over potential problems that they have yet to experience. Because this is such a widespread attitude, the 6.0L-powered Super Duty has depreciated significantly in value, offering resale values which are relatively low compared to the very high purchase price the trucks originally demanded, leading to losses which are greater than the cost of maintenance and upgrades which significantly improve the reliability of the 6.0L. The upgrades and maintenance procedures recommended by Fleet Service Northwest, Inc., are the subject of this section.

Engine Oil Cooler Answers

As explained above, the engine oil cooler is a significant reliability issue with the 6.0L. Replacing the oil cooler with another stock oil cooler will provide a temporary fix with a very predictable repeat failure. Fortunately there is a permanent solution which has been developed by Bulletproof Diesel. The Bulletproof Engine Oil Cooler system for the 6.0L has proven to be a great improvement over the stock cooler, not only in its proven reliability, but also in its improved cooling of engine oil. One major advantage of the oil to air cooler is that the heat from the engine oil is passed into the airstream rather than through the engines cooling system. Under some of the most severe conditions such as towing a heavy load up steep grades, we have seen a 10 to 15 degree reduction in oil temperatures.

The Bulletproof Engine Oil Cooler is an air-to-oil cooler which mounts to the rear of the air conditioning condenser. This mounting location allows optimal cooling of engine oil without reducing the performance of the vehicle's air conditioning system. Installation of this cooler helps to reduce engine oil temperatures, especially when towing heavy loads, and eliminates the recurring problems for which the stock engine oil cooler is notorious.

The Bulletproof Engine Oil Cooler kit includes everything which is necessary to install the engine oil cooler, including the oil transfer block, and remote-mounted engine oil filter system. The Full Bulletproof Kit also includes a Bulletproof EGR Cooler at a discounted price compared to buying the coolers separately.

EGR Cooler Answers

The EGR Cooler is another significant source of Powerstroke trouble which Bulletproof Diesel has addressed for both the 6.0L and 6.4L engines. The Bulletproof EGR Coolers for both engines feature lifetime warranties, and have already proven to be a great way to permanently solve an otherwise recurring problem with these engines. The Bulletproof coolers accomplish this through much more robust construction than the stock coolers, and by holding a higher volume of coolant, reducing the likelyhood of coolant boiling within the cooler. This is done without taking up additional space within the engine compartment, as the Bulletproof EGR Coolers are actually made by replacing the internal components in a stock cooler.

Bulletproof Diesel products are available for installation or purchase at factory-direct prices from Fleet Service Northwest, Inc.

Check out our Ford Diesel Store for details.

Turbocharger Answers

While options for upgrading the turbochargers on the 6.0L are extremely limited and unlikely to provide any significant reliability improvements, there are preventive steps that can be taken to reduce the recurrence of turbocharger problems. First, running good quality Ultra-Low Sulfur Diesel, maintaining clean fuel filters, and avoiding fuel system contamination can reduce the production of carbon, lessening the slow buildup of carbon inside the VGT. Addressing misfires, smoke, and low power conditions as quickly as possible can also help prevent rapid buildup of carbon, along with potentially avoiding other serious engine damage that can result from these conditions.

Keeping your control module software updated is one of the best ways to increase the reliability of your VGT. New control module software programs will perform VGT duty cycle sweeps, helping to clear carbon buildup and prevent sticking of the VGT. Fleet Service Northwest can perform control module software updates on all Ford vehicles, as well as several other vehicle makes.

Use of performance programmers and tuners should also be done with care, and exhaust gas temperature, or "pyro" monitors should be installed and observed by the driver under hard acceleration, when towing, or when pulling hills when using increased-horsepower settings.

EGR Valve Answers

There are several EGR delete kits available to eliminate the EGR system on the 6.0L Powerstroke, including the Bulletproof EGR Delete. We recommend maintaining the operation of your EGR system, for the reasons explained in our 6.0L EGR Delete Concerns article. The availability of the Bulletproof EGR Cooler allows the 6.0L's EGR system to perform extremely reliably in nearly all applications, since the largest problem by for is coolant loss through a leaking stock EGR cooler. Issues with the valves themselves are fairly common, and are more common with trucks that idle for significant periods. Sticking EGR valves can generally be cleaned, and care should be taken to avoid allowing contaminants entering the solenoid through the two vent holes on the bottom, cleaning agents can reach the position sensor at the top of the EGR valve while the valve is held in an inverted position during cleaning. Inverting the valve while cleaning should be avoided. Solvents and cleaners can not only damage the valve position sensor if it enters the vent holes, but it can also damage the shaft seal on the valve allowing hot gasses to pass into the EGR valve during operation, leading to an electrical failure of the valve itself. Cleaning is generally a successful way of maintaining proper EGR valve operation and will greatly extend the service life of the valve. As with VGT issues, the source of the coking or deposits should be investigated and repaired. The major causes for these deposits are periods of extended idle, fuel quality, excessive crankcase pressure or malfunctioning crankcase ventilation/oil mist separator system and degraded engine oil due to improper and extended engine oil service intervals.

It is also a common misconception that removing the EGR system will lower exhaust gas temperatures and increase peak horsepower. EGR systems are actually designed to lower combustion temperatures, and disabling the EGR system will actually raise exhaust gas temperatures under some conditions, while never lowering them. EGR systems also do not operate under high throttle application, meaning that properly working EGR systems have no effect on horsepower when high power is demanded by the driver. For these reasons, we recommend upgrading to a Bulletproof EGR Cooler rather than installation of an EGR delete.

Head Gasket Answers

Our experience with head gasket failure on the 6.0L Powerstroke has shown that proper installation of ARP Head Studs is a long-term solution, and one that can be performed preventively with great results. Most 6.0L owners do wait until they experience head gasket failure to perform a head stud installation, but given the inevitability of this failure, preventive installation of a headstud kit can be a great way to improve the quality of the 6.0L Powerstroke and prevent additional damage that can result from head gasket failure. It is essential that machining of the cylinder head surfaces is performed when replacing head gaskets, despite Ford's stance that the heads cannot be machined. Preventive installation of ARP Head Studs should always be considered when replacing an EGR cooler or engine oil cooler, as this is approximately 1/3 of the labor required to replace head gaskets and would have to be repeated upon head gasket failure.

For trucks with a stock EGR cooler, upgrading or deleting the EGR Cooler should be considered a mandatory part of performing a head stud installation. At minimum, the stock engine oil cooler should be replaced with a new stock cooler, and a Bulletproof Engine Oil Cooler should be considered at this time, since it adds only minimal labor when done in combination with head gasket or EGR cooler replacement. Installing upgraded head studs, EGR cooler, and engine oil cooler all at once is the most economical way to eliminate the most severe, otherwise recurring, reliability problems that the 6.0L Powerstroke faces.

Fuel Injection System Answers

As described above, the 6.0L's fuel injectors are lubricated by fuel, and are sensitive to fuel shortages and fuel quality issues. Using Motorcraft fuel filters and replacing them frequently is a good way to lessen the risk of fuel injector damage. Motorcraft fuel filters for both the 6.0L and 6.4L have patented features that are not available even on high-quality aftermarket filters, and as a result, filter water better than most aftermarket filters.

Fuel quality and refueling practices are of equal importance, since contaminants in fuel both cause direct damage and will cause fuel filters to clog more quickly. Fuel shortages due to clogged filters cause fuel injectors to run without lubrication. For this reason, it is essential that only Ultra-Low Sulfur Diesel is run in 6.0L Powerstroke engines, and that fuel filler caps be kept clean and in good condition. Many biodiesels, along with Low-Sulfur Diesel (as opposed to Ultra-Low-Sulfur Diesel), may contain particles which can not only accelerate filter clogging, but can also cause faster wear of precision fuel injection components as some particles will always manage to get past the filter. Fuel supplied by some mobile refueling services can also be problematic if their tanks are not properly maintained and fuel is not properly filtered as it is dispensed. Similarly, refueling in the field from fuel cans should be done with care and as infrequently as possible, since contaminants can easily enter the fuel can or the vehicle's fuel filler neck, particularly at dusty or dirty jobsites. Sealing surfaces of fuel filler caps should also be checked periodically for wear, since dust and debris can enter the fuel filler via a worn fuel filler cap seal.

Checking engine oil on a regular basis and servicing the engine with Motorcraft's Super Duty Diesel Engine Oil is a great way to protect the engine from wear and damage, including damage to the high-pressure oil pump (HPOP) system and high-pressure oil-operated fuel injectors. Maintaining and upgrading the engine oil cooler is also important, as explained above and in our 6.0L EGR/Oil Cooler Upgrade article.

The Full Bulletproof Package

The Full Bulletproof Package is the most economical way to upgrade all of the 6.0L's most serious reliability issues, and includes ARP Head Stud installation combined with Bulletproof EGR and Engine Oil Cooler installation, all at one time. The economy of this service comes from the elimination of repeated labor which would be required if performing each of these upgrades separately. Replacing the EGR cooler and replacing or upgrading the engine oil cooler both require removal of the intake manifold. The labor for each of these services accounts for approximately 1/3 of the labor required for head gasket replacement. For this reason, we recommend that trucks experiencing EGR cooler and engine oil cooler failures receive an ARP Head Stud installation in combination with these repairs.

It has been our experience that many trucks which experience stock EGR cooler failure, and do not receive ARP Head Stud installation at the same time, will experience head gasket failure in a short period of time following EGR cooler failure. This may be attributed to the EGR cooler failure itself, as described above, as well as to the general problem of 6.0L head gasket failure. Even if EGR cooler failure has not contributed in a significant way to head gasket failure, it is a predictable and preventable failure which is more economical to address preventively in combination with, rather than separate from, EGR and engine oil cooler upgrade and repair.

The Decision

Now that we've gone through the 6.0L's more common problems, and the recommended repairs, it may seem to some owners that these trucks aren't worth keeping due to high maintenance costs, especially if you're facing one of the more major repairs at this time. It is important to take all factors into account when considering replacing a truck, since even major repairs are usually a more economical choice. The biggest factor is of course the purchase price of a new or used truck compared to the trade-in value of a 6.0L-powered truck. As mentioned before, the value of these trucks has depreciated due to their perceived widespread problems, and the resulting desire of many owners to replace them with Duramax and Cummins-powered trucks, or other Ford trucks for that matter, has helped keep the resale value of these other trucks high. A new truck payment may be $700 or more, and still requires periodic preventive maintenance, meaning that a new truck may cost $10,000 a year just in payments and maintenance for the first few years. The 2003.25 to 2007 6.0 Super Duty is currently the best value in used trucks out there. with the addition of these well proven upgrades, this truck will provide you many years of reliable service.

A Diesel powered Super Duty is more of an investment than a gasoline powered truck. a premium was paid for this option on initial purchase and the 6.0l super duty is generally more expensive when purchased used as well.maintenence cost's are higher for the Diesel as many owners realize, but performing maintenence at the recommended intervals, and modifying maintenence to meet the needs of the 6.0l and your particular use will ensure a long service life.

Most 6.0L trucks are paid for by now, or are nearly paid for, and even in some worst-case scenarios, average yearly maintenance will not come close to the cost of a new truck. Add this to the fact that the Ford Super Duty chassis is more robust and more capable than any other chassis in the light truck market. The powertrains on other trucks may lack the major reliability issues, but the trucks themselves just don't measure up to the legendary Super Duty chassis.

If repairs and upgrades are performed correctly, and the preventive maintenance procedures recommended in this article and by the manufacturer are performed, the 6.0L Powerstroke can serve its owners economically for years to come.

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