Up next Covid Drag Racing at Wagler Motorsports Park Published on January 06, 2021 Author Mike McGlothlin Tags Cummins, Diesel, diesel engine, Diesel Exhaust, Diesel Truck, diesel world, Engine Maintenance, Engine Modification, Engine Mods, ford, Ford Diesel, GM, gm diesel, power stroke, turbo, Turbocharged, turbocharger, Share article Facebook 0 Twitter 0 Mail 0 The 6.0L Power Stroke How You Can Make Your 6.0L More Dependable Perhaps no other diesel engine in recent memory has burdened its owners more than the 6.0L Power Stroke. Thousands of roadside repairs, expensive tow bills, and repeat failures plague the ’03-’07 Super Duty. Rumor has it that Ford even entertained the idea of buying Duramax engines from GM for use in its trucks during this timeframe… Powerful, yes. Reliable, no. You can virtually point to any component on the 6.0L other than its rotating assembly and associate some form of poor engineering or premature failure with it. Exhaust gas recirculation system, oil cooler, head gasket, injector, high-pressure oil pump, FICM, and turbocharger issues all run rampant—several of which strike within the first 100,000 miles To be fair, some 6.0L’s do go the distance, but it’s very rare to find one with a quarter-million miles on the clock and no history of at least some sort of significant repair. In the following pages, we’ll walk you through all of the 6.0L’s common failure points, starting with the most prevalent offenders. Fortunately for all of us in 2020, 99-percent of the 6.0L’s problems have been thoroughly documented by mechanics and addressed by the diesel world’s thriving aftermarket. We’ll conclude with a list of must-have upgrades that no 6.0L Power Stroke should be forced to live without. You’re looking at the biggest failure point on the 6.0L Power Stroke. No, it’s not the EGR cooler and no, it’s not the head bolts. It’s the stacked plate heat exchanger portion of the oil cooler assembly that wreaks the most havoc on the engine. It’s notorious for its internal coolant passages clogging and blocking the coolant flow that’s vital for keeping engine oil temperature in check. With the 6.0L’s HEUI injection system pressurizing the engine oil as high as 3,600 psi in stock form (and 4,000 psi or more in high horsepower applications), some pretty serious heat gets generated. Throw in an inability to effectively cool the oil and, sooner or later, you’ve got serious problems. The miniscule coolant passageways within the oil cooler are prone to clogging due to debris present in the cooling system. This debris is made up of casting sand from the block or suspended deposits from using the incorrect coolant for the engine. Oftentimes it’s a combination of both. In blown head gasket scenarios, where combustion gases are allowed to enter the coolant, carbon contaminates also become lodged in the oil cooler’s tiny passages. Once coolant flow through the oil cooler stops, oil temps sky-rocket. Unfortunately, a failing oil cooler can go unnoticed for thousands of miles if you don’t have a way to precisely monitor engine oil temp and coolant temp simultaneously (the dummy gauges in the factory cluster won’t suffice). The general consensus is that both EOT and ECT should stay within 15 degrees of each other, but you should start watching things closely once a 10-degree difference between the two persists. Nearly 90-percent of all EGR cooler failures are a direct result of a plugged oil cooler. Because the coolant blockage in the oil cooler also starves the EGR cooler of the coolant it needs to function properly (remember, the EGR cooler is exposed to 1,200 degree EGT or more), the welds on its core eventually rupture. Once that occurs, you’ve got coolant entering the exhaust (or even the intake) and copious amounts of white smoke leaving the tailpipe. Sadly, it’s not uncommon for an EGR cooler failure to be misdiagnosed, where only the EGR cooler gets replaced and the plugged oil cooler goes unaddressed— which predictably toasts the new EGR cooler in short order. The other 10-percent of the time, the EGR cooler plugs up with soot, carbon, and oil vapor deposits. And for as many updates and improvements Ford implemented on the 6.0L throughout its production run, surprisingly it’s the ’03 style, circular tube EGR cooler that lives the longest (right). This is due to its larger internal passageways. The later, square-shaped cooler employed on the ’04-’07 engines was prone to plugging much sooner (left). Positioned downwind of the EGR cooler and at the front of the intake manifold, the EGR valve routes exhaust gases back into the 6.0L’s intake tract. Rather than some modern EGR valves, which have been located on the hot-side to help cut soot accumulation, it tends to plug up quickly—oftentimes within 20,000 miles. Once the deposits add up, the valve will stick and the truck will suffer from hesitation, excessive smoke, and low power. It’s no secret that EGR is a nasty business in diesel engines, coating everything in its path with a sooty, sticky grime that’s nearly impossible to remove. Affected components include the aforementioned EGR valve and EGR cooler, the intake manifold, cylinder heads, and especially sensors. The intake air temperature (IAT) sensor shown here was chock full of gunk after just 19,000 miles, which should give you an idea what the living conditions are like inside the 6.0L’s intake manifold. Even with a perfectly healthy oil cooler, the 6.0L’s EGR system is extremely hard on engine coolant. On top of circulating through the heads and block, it’s indirectly exposed to exhaust gas temps that often exceed 1,000 degrees F. This is why it’s so important to not only run the correct antifreeze in your 6.0L, but to change it at the recommended interval (100,000 miles/5 years initially, then every 45,000 miles/3 years). Here you can see what an overdue coolant flush looks like (from left to right), with five flushes being required to fully clean out the cooling system. Head to block clamping force is extremely important in any diesel engine thanks to the immense cylinder pressure they produce. Most industrial-grade diesels incorporate at least six head bolts per cylinder, which includes both the Cummins and Duramax competition. Unfortunately for power junkies, Navistar designed the 6.0L Power Stroke platform to employ just four fasteners per cylinder (10 per bank). At the factory 325hp rating, this proves sufficient for the most part (although stock trucks that tow heavy can still lift the heads), but adding 160- rwhp through the use of a programmer pushes them to the brink. An even bigger problem than having just four head bolts per cylinder is the fact that they only measure 14mm in diameter. If you’ve spent any amount of time around the 6.4L Power Stroke, you know that they blow head gaskets much less often than the 6.0L (and usually while making 100hp or more). This is because the head bolts were upsized to 16mm in diameter on the 6.4L. Torque to yield head bolts are nothing new, but once they stretch beyond their yield point permanent elongation occurs. At this point the TTY fastener will never have the same clamping force it did when it left the factory. With the added cylinder pressure (i.e. torque) that comes with aggressive tuning, it doesn’t take long for them to stretch enough to allow combustion gases to escape. One dead giveaway that a 6.0L has lost a head gasket (possibly even both of them) looks like this: coolant residue all over the degas bottle. Once a head lifts and compression sneaks by the gasket the cooling system becomes pressurized. To ensure the heads don’t become warped beyond repair, it’s best to pull the heads and fix the issue as soon as it’s noticed. The 6.0L Power Stroke’s injectors are one area where the failure rate seems to have been exaggerated a bit over the years. While they aren’t perfect, the 6.0L’s injectors are reliable when treated to proper maintenance (regular oil changes and new fuel filters), clean fuel, and fed sufficient supply pressure from the lift pump. However, if coolant makes its way into the oil, they can head south quickly. Believe it or not, a lot of injector-related issues revolve around improper installation (such as a rolled O-ring, over-tightened injector holddown, or hold-downs that haven’t been torque enough). The primary reason the 6.0L’s injectors get such a bad rap has to do with stiction above anything else. A phenomenon where oil coking causes friction within the spool valve along with hindering oil flow (remember, the spool valve is what allows high-pressure oil to enter the injector), stiction is behind most of the rough cold starts the 6.0L is notorious for. With stiction in the mix, the injectors’ inability to fire properly leads to poor and inconsistent in-cylinder atomization, excess smoke, erratic idle, and failed cylinder contribution tests. High-pressure oil issues are extremely common on the 6.0L, which was rarely ever a concern with the HEUI-fired 7.3L that preceded it. Even the high-pressure oil pumps themselves fail. For whatever the reason, the HPOP’s on ’03-’04 engines seem to keep operating as they become weaker while later pumps (’05-‘07) tend to either be good or bad. A suspected bad HPOP will fail to build enough injection control pressure (ICP) to start the engine, but it warrants a look at the IPR valve first. If the screen on the end of the IPR has been damaged chances are good that the pump ingested something. One of the more infamous issues ’04.5-’07 6.0L owners face is a hard-start or no-start condition when warm. Nine times out of 10 the culprit is the snap-to-connect (STC) fitting on the back of the high-pressure oil pump that links the HPOP’s outlet to the branch tubes (which route oil into the stand-pipes, and then on to the oil rails in each head). As the branch tubes vibrate and flex, the STC fitting’s two-piece seal sees excessive wear, and eventually begins to leak oil. When the engine is cold and the oil is thick, it starts like normal, but when it’s warm (and the oil is thinner) it won’t fire off again. Adding insult to injury, the 6.0L’s HPOP is gear-driven at the back of the engine under its own cover, which means accessing the STC fitting calls for a healthy amount of labor. Long crank, no-start, surging throttle, rough idle, high IPR duty cycle readings, and poor performance are all symptoms of a high-pressure oil leak somewhere in the 6.0L’s HEUI system. Oftentimes the leak is traced back to a bad O-ring on a high-pressure stand pipe (shown), a dummy plug, a cracked branch tube, or the aforementioned STC fitting on the back of the HPOP. Many of the 6.0L’s drivability complaints are associated with sticking vanes in the Garrett GT3782VA turbocharger. This issue is common in trucks that spend the majority of their time idling, steady-state cruising, or parked in the driveway. When the moveable vanes (which vary the amount of exhaust gases directed across the turbine wheel) aren’t exercised regularly, they can fail to move at all. Turbo lag or zero high rpm power and a P0299 code stored in the PCM are telltale signs that it’s time to clean the turbo. Functionality of the electronically controlled variable geometry turbocharger is highly reliant on a working exhaust backpressure (EBP) sensor and a clean line spanning from the EBP sensor to the driver side exhaust manifold. If the sensor fails or the line plugs up, an inaccurate back pressure reading is sent to the PCM, a P0470 and/or P0299 code can be thrown, and the turbo’s VGT operation will be hindered. A seized unison ring is almost always the guilty party in a stuck turbo situation. The unison ring is the component that moves all of the variable vanes at once. When it hasn’t seen its full operating range in a while, rust and corrosion tends to form, causing it to cement itself in one position. In most cases, pulling the turbo and treating it to a thorough cleaning by way of a Scotch-Brite pad and a die grinder is all that’s required to get the VGT fully functional again. Perhaps the sneakiest killer of 6.0L performance is the fuel injection control module (FICM). Tasked with sending the precise voltage to each injector solenoid in order to fire it, the FICM has to operate at 48-volts at all times, including at key-on and while cranking the engine over. What newcomers and outsiders to the 6.0L world don’t know is that when the batteries become weaker and the engine gets harder and harder to start, the FICM is dying as well. As the driver side of the FICM fails, the FICM will gradually send lower and lower voltage the injectors’ way, all while performance suffers. It’s common to find hairline cracks in the 6.0L’s cast-iron cylinder heads (and the same goes for the 6.4L’s heads), but once they protrude into the valve seats it’s time to start over. A crack that spans into an exhaust valve seat is usually a hint that the engine saw elevated EGT on more than one occasion, and maybe even a fair amount of abuse. Subscribe Our Weekly Newsletter FREQUENTLY ASKED QUESTIONS What are the benefits of the 6.0L Power Stroke Diesel’s design, such as the number of valves per cylinder? Benefits of the 6.0L Power Stroke Diesel Design Enhanced Airflow for Increased Power The 6.0L Power Stroke Diesel engine is equipped with four valves per cylinder. This design optimizes airflow, which in turn boosts engine power and efficiency. By allowing air to move more freely into and out of the combustion chamber, the engine can produce more power while maintaining fuel efficiency. Fast Warm-Up for Comfort and Convenience Another advantage of this engine is its ability to warm up rapidly. This feature is particularly useful in cold weather conditions. The engine quickly heats the cabin, ensuring a comfortable interior environment for passengers. Additionally, it effectively clears the windshield, providing drivers with increased visibility and safety from the start of their journey. Efficient Maintenance with Easy Access For maintenance and serviceability, the glow plugs in the 6.0L Power Stroke Diesel are designed to be externally accessible. This arrangement means they can be reached without the need to remove valve covers, which simplifies the servicing process. As a result, it saves time and effort, reducing downtime and promoting cost-effective maintenance. What is the historical significance of the diesel engine series? The Historical Significance of the Diesel Engine Series The diesel engine series has played a pivotal role in transforming the automotive landscape. These engines are celebrated for their durability, power, and efficiency, marking significant milestones in vehicle technology. Evolution and Innovation Early Developments: Initially harnessed for their robust power, diesel engines quickly became the backbone for commercial and industrial vehicles, thanks to their efficiency and reliability. Technological Advancements: Over the decades, advancements in turbocharging and direct fuel injection have enhanced performance and fuel economy. This has solidified their place in sectors that demand both strength and endurance. Impact on Industry Trucking and Transportation: The introduction of diesel engines into trucks and buses revolutionized long-distance travel and logistics, facilitating faster and more cost-effective delivery of goods and passengers. Agricultural and Construction Machinery: Diesel engines have powered tractors, construction equipment, and other heavy-duty machinery, boosting productivity and efficiency in these industries. Environmental and Economic Influence In recent years, innovations have focused on reducing emissions without sacrificing performance. This shift supports global efforts toward more sustainable transportation solutions and highlights the diesel engine’s evolving role in balancing environmental concerns with economic needs. Overall, the diesel engine series has not just powered vehicles; it has powered progress across various sectors, cementing its historical significance in the modern world. What types of information sheets are available for the 6.0L engine? Information Sheets Available for the 6.0L Engine If you’re looking to get in-depth details about the 6.0L engine, several information sheets can offer invaluable insights and guidance. These documents are essential for anyone interested in remanufactured engines, maintenance, or installation. Here’s what you can find: Engine Remanufacturing Details 6.0L Diesel Engine Specs (2003-2007): Comprehensive technical information on models spanning these years. Remanufactured Long Block Options: Information on 6.0L and 6.4L long block stripped engines, describing the components and specifications. Maintenance and Installation Guides Head Gasket and Kits: Detailed guides on head gasket options, including assembly instructions and compatibility. Head Bolts and Studs: Comparative insights to help decide between bolts or studs for head installation. Component-Specific Information Diesel Injectors: Sheets with technical specifications and installation overviews for the 6.0L diesel injectors. Turbochargers: Information covering remanufactured turbocharger options, including performance metrics and installation tips. These information sheets are tailored to assist both professional mechanics and DIY enthusiasts in navigating the complexities of the 6.0L engine, providing useful tips and technical details for optimal repair and maintenance. How does the 6.0L engine ensure efficient and long-lasting performance? To be fair, some 6.0L’s do go the distance, but it’s very rare to find one with a quarter-million miles on the clock and no history of at least some sort of significant repair. In the following pages, we’ll walk you through all of the 6.0L’s common failure points, starting with the most prevalent offenders. Fortunately for all of us in 2020, 99-percent of the 6.0L’s problems have been thoroughly documented by mechanics and addressed by the diesel world’s thriving aftermarket. We’ll conclude with a list of must-have upgrades that no 6.0L Power Stroke should be forced to live without. Enhancing Performance and Longevity Despite its reputation, the 6.0L engine includes features designed to boost its efficiency and durability. Consider the following: Premium Silicon Seals: These seals on O-ring fittings ensure excellent oil flow, a critical factor in maintaining engine health and performance over time. Easy-Access Oil Filter: With a top-mounted cartridge design, routine maintenance becomes a breeze. No need to crawl under the vehicle, which encourages regular upkeep and contributes to long-lasting operation. Stainless Steel, Multi-Layer Head Gaskets: Built for durability, these gaskets are key in preventing leaks and ensuring the engine runs smoothly under demanding conditions. By incorporating these elements, the 6.0L engine lays down a foundation aimed at efficient, long-lasting performance. However, as we examine the common failure points, it becomes clear why aftermarket upgrades are often necessary to fully realize the engine’s potential. What components are used to enhance the durability of the engine? The use of stainless steel, multi-layer head gaskets contributes to the engine’s robustness and longevity. How is routine maintenance made easier on the 6.0L engine? Maintenance is simplified by the oil filter’s top-mounted cartridge design, allowing easy access without needing to get underneath the vehicle. What features contribute to the oil flow efficiency of the 6.0L engine? The engine features high-quality silicon seals on its O-ring fittings, which enhance the flow of oil throughout the system. What performance features does the 6.0L diesel engine offer? The 6.0L Power Stroke How You Can Make Your 6.0L More Dependable Perhaps no other diesel engine in recent memory has burdened its owners more than the 6.0L Power Stroke. Thousands of roadside repairs, expensive tow bills, and repeat failures plague the ’03-’07 Super Duty. Rumor has it that Ford even entertained the idea of buying Duramax engines from GM for use in its trucks during this timeframe… Powerful, yes. Reliable, no. You can virtually point to any component on the 6.0L other than its rotating assembly and associate some form of poor engineering or premature failure with it. Exhaust gas recirculation system, oil cooler, head gasket, injector, high-pressure oil pump, FICM, and turbocharger issues all run rampant—several of which strike within the first 100,000 miles. To be fair, some 6.0L’s do go the distance, but it’s very rare to find one with a quarter-million miles on the clock and no history of at least some sort of significant repair. In the following pages, we’ll walk you through all of the 6.0L’s common failure points, starting with the most prevalent offenders. Fortunately for all of us in 2020, 99-percent of the 6.0L’s problems have been thoroughly documented by mechanics and addressed by the diesel world’s thriving aftermarket. We’ll conclude with a list of must-have upgrades that no 6.0L Power Stroke should be forced to live without. Unpacking the Performance Features Despite its notorious reliability issues, the 6.0L Power Stroke was designed with several performance-enhancing features. These include: Variable Geometry Turbocharger: This helps maximize responsiveness, a crucial factor in performance diesel engines. 5-Speed TorqShift™ Automatic Transmission: Known for its acceleration, drivability, and low-end torque, it contributes significantly to the engine’s performance. Durable, Rigid Cast Iron Bedplate: Provides structural integrity and support, crucial for handling high-pressure operations. Multi-Layer Stainless Steel Head Gaskets: Offer durability and help maintain engine performance under stress. Externally Accessible Glow Plugs: Facilitate easier maintenance and improved cold-start performance. Hydraulic Roller Followers: Eliminate valve lash adjustments, simplifying upkeep. Easily Accessible Cartridge-Style Fuel and Oil Filters: Designed to simplify routine maintenance, reducing downtime. The Biggest Failure Point You’re looking at the biggest failure point on the 6.0L Power Stroke. No, it’s not the EGR cooler and no, it’s not the head bolts. It’s the stacked plate heat exchanger portion of the oil cooler assembly that wreaks the most havoc on the engine. It’s notorious for its internal coolant passages clogging and blocking the coolant flow that’s vital for keeping engine oil temperature in check. With the 6.0L’s HEUI injection system pressurizing the engine oil as high as 3,600 psi in stock form (and 4,000 psi or more in high horsepower applications), some pretty serious heat gets generated. Throw in an inability to effectively cool the oil and, sooner or later, you’ve got serious problems. By addressing these core issues and leveraging the performance features, owners can transform the 6.0L from a source of frustration to a dependable powerhouse. What specific components are designed for efficiency and longevity? Components such as premium silicon seals on O-ring fittings, which help ensure optimal oil flow, and multi-layer stainless steel head gaskets are designed for efficiency and long-term durability. How is routine maintenance made easier? Routine maintenance is simplified with features like externally accessible glow plugs and cartridge-style fuel and oil filters that can be easily reached, eliminating the need to access hard-to-reach areas. What materials and design elements contribute to the engine’s durability? The engine utilizes a rigid cast iron bedplate and multi-layer stainless steel head gaskets, both contributing to its robust and durable design. What features enhance the engine’s performance? The engine’s performance is boosted by a variable geometry turbocharger, which optimizes responsiveness, and a 5-speed TorqShift™ automatic transmission that enhances acceleration, drivability, and low-end torque. What are the notable features of the 6.0L engine? The 6.0L Power Stroke How You Can Make Your 6.0L More Dependable Perhaps no other diesel engine in recent memory has burdened its owners more than the 6.0L Power Stroke. Thousands of roadside repairs, expensive tow bills, and repeat failures plague the ’03-’07 Super Duty. Rumor has it that Ford even entertained the idea of buying Duramax engines from GM for use in its trucks during this timeframe… Powerful, yes. Reliable, no. You can virtually point to any component on the 6.0L other than its rotating assembly and associate some form of poor engineering or premature failure with it. Exhaust gas recirculation system, oil cooler, head gasket, injector, high-pressure oil pump, FICM, and turbocharger issues all run rampant—several of which strike within the first 100,000 miles. To be fair, some 6.0Ls do go the distance, but it’s very rare to find one with a quarter-million miles on the clock and no history of at least some sort of significant repair. In the following pages, we’ll walk you through all of the 6.0L’s common failure points, starting with the most prevalent offenders. Fortunately for all of us in 2020, 99-percent of the 6.0L’s problems have been thoroughly documented by mechanics and addressed by the diesel world’s thriving aftermarket. We’ll conclude with a list of must-have upgrades that no 6.0L Power Stroke should be forced to live without. Notable Features of the 6.0L Engine Variable Geometry Turbocharger: Helps maximize responsiveness, delivering a punchy performance when you need it. 5-Speed Automatic Transmission: The TorqShift™ automatic transmission provides smooth acceleration, drivability, and impressive low-end torque. Durable Components: Includes a rigid cast iron bedplate and multi-layer stainless steel head gaskets, designed for longevity. Maintenance-Friendly Design: Externally accessible glow plugs and cartridge-style fuel and oil filters make routine maintenance straightforward. Hydraulic Roller Followers: These eliminate the need for valve lash adjustments, reducing long-term maintenance requirements. Key Failure Points and Solutions You’re looking at the biggest failure point on the 6.0L Power Stroke. No, it’s not the EGR cooler and no, it’s not the head bolts. It’s the stacked plate heat exchanger portion of the oil cooler assembly that wreaks the most havoc on the engine. It’s notorious for its internal coolant passages clogging and blocking the coolant flow that’s vital for keeping engine oil temperature in check. With the 6.0L’s HEUI injection system pressurizing the engine oil as high as 3,600 psi in stock form (and 4,000 psi or more in high horsepower applications), some pretty serious heat gets generated. Throw in an inability to effectively cool the oil and, sooner or later, you’ve got serious problems. The miniscule coolant passageways within the oil cooler are prone to clogging due to debris present in the cooling system. This debris is made up of casting sand from the block or suspended deposits from using the incorrect coolant for the engine. Oftentimes it’s a combination of both. In blown head gasket scenarios, where combustion gases are allowed to enter the coolant, carbon contaminates also become lodged in the oil cooler’s tiny passages. Once coolant flow through the oil cooler stops, oil temps sky-rocket. Unfortunately, a failing oil cooler can go unnoticed for thousands of miles if you don’t have a way to precisely monitor engine oil temp and coolant temp simultaneously (the dummy gauges in the factory cluster won’t suffice). The general consensus is that both EOT and ECT should stay within 15 degrees of each other, but you should start watching things closely once a 10-degree difference between the two persists. Nearly 90-percent of all EGR cooler failures are a direct result of a plugged oil cooler. Because the coolant blockage in the oil cooler also starves the EGR cooler of the coolant it needs to function properly (remember, the EGR cooler is exposed to 1,200 degree EGT or more), the welds on its core eventually rupture. Once that occurs, you’ve got coolant entering the exhaust (or even the intake) and copious amounts of white smoke leaving the tailpipe. Sadly, it’s not uncommon for an EGR cooler failure to be misdiagnosed, where only the EGR cooler gets replaced and the plugged oil cooler goes unaddressed— which predictably toasts the new EGR cooler in short order. The other 10-percent of the time, the EGR cooler plugs up with soot, carbon, and oil vapor deposits. And for as many updates and improvements Fordimplemented on the 6.0L throughout its production run, surprisingly it’s the ’03 style, circular tube EGR cooler that lives the longest (right). This is due to its larger internal passageways. The later, square-shaped cooler employed on the ’04-’07 engines was prone to plugging much sooner (left). Positioned downwind of the EGR cooler and at the front of the intake manifold, the EGR valve routes exhaust gases back into the 6.0L’s intake tract. Rather than some modern EGR valves, which have been located on the hot-side to help cut soot accumulation, it tends to plug up quickly—oftentimes within 20,000 miles. Once the deposits add up, the valve will stick and the truck will suffer from hesitation, excessive smoke, and low power. It’s no secret that EGR is a nasty business in diesel engines, coating everything in its path with a sooty, sticky grime that’s nearly impossible to remove. Affected components include the aforementioned EGR valve and EGR cooler, the intake manifold, cylinder heads, and especially sensors. The intake air temperature (IAT) sensor shown here was chock full of gunk after just 19,000 miles, which should give you an idea what the living conditions are like inside the 6.0L’s intake manifold. Even with a perfectly healthy oil cooler, the 6.0L’s EGR system is extremely hard on engine coolant. On top of circulating through the heads and block, it’s indirectly exposed to exhaust gas temps that often exceed 1,000 degrees F. This is why it’s so important to not only run the correct antifreeze in your 6.0L, but to change it at the recommended interval (100,000 miles/5 years initially, then every 45,000 miles/3 years). Here you can see what an overdue coolant flush looks like (from left to right), with five flushes being required to fully clean out the cooling system. Head to block clamping force is extremely important in any diesel engine thanks to the immense cylinder pressure they produce. Most industrial-grade diesels incorporate at least six head bolts per cylinder, which includes both the Cummins and Duramax competition. Unfortunately for power junkies, Navistar designed the 6.0L Power Stroke platform to employ just four fasteners per cylinder (10 per bank). At the factory 325hp rating, this proves sufficient for the most part (although stock trucks that tow heavy can still lift the heads), but adding 160-rwhp through the use of a programmer pushes them to the brink. An even bigger problem than having just four head bolts per cylinder is the fact that they only measure 14mm in diameter. If you’ve spent any amount of time around the 6.4L Power Stroke, you know that they blow head gaskets much less often than the 6.0L (and usually while making 100hp or more). This is because the head bolts were upsized to 16mm in diameter on the 6.4L. Torque to yield head bolts are nothing new, but once they stretch beyond their yield point permanent elongation occurs. At this point the TTY fastener will never have the same clamping force it did when it left the factory. With the added cylinder pressure (i.e. Torque) that comes with aggressive tuning, it doesn’t take long for them to stretch enough to allow combustion gases to escape. One dead giveaway that a 6.0L has lost a head gasket (possibly even both of them) looks like this: coolant residue all over the degas bottle. Once a head lifts and compression sneaks by the gasket the cooling system becomes pressurized. To ensure the heads don’t become warped beyond repair, it’s best to pull the heads and fix the issue as soon as it’s noticed. The 6.0L Power Stroke’s injectors are one area where the failure rate seems to have been exaggerated a bit over the years. While they aren’t perfect, the 6.0L’s injectors are reliable when treated to proper maintenance (regular oil changes and new fuel filters), clean fuel, and fed sufficient supply pressure from the lift pump. However, if coolant makes its way into the oil, they can head south quickly. Believe it or not, a lot of injector-related issues revolve around improper installation (such as a rolled O-ring, over-tightened injector holddown, or hold-downs that haven’t been torque enough). The primary reason the 6.0L’s injectors get such a bad rap has to do with stiction above anything else. A phenomenon where oil coking causes friction within the spool valve along with hindering oil flow (remember, the spool valve is what allows high-pressure oil to enter the injector), stiction is behind most of the rough cold starts the 6.0L is notorious for. With stiction in the mix, the injectors’ inability to fire properly leads to poor and inconsistent in-cylinder atomization, excess smoke, erratic idle, and failed cylinder contribution tests. High-pressure oil issues are extremely common on the 6.0L, which was rarely ever a concern with the HEUI-fired 7.3L that preceded it. Even the high-pressure oil pumps themselves fail. For whatever the reason, the HPOP’s on ’03-’04 engines seem to keep operating as they become weaker while later pumps (’05-‘07) tend to either be good or bad. A suspected bad HPOP will fail to build enough injection control pressure (ICP) to start the engine, but it warrants a look at the IPR valve first. If the screen on the end of the IPR has been damaged chances are good that the pump ingested something. One of the more infamous issues ’04.5-’07 6.0L owners face is a hard-start or no-start condition when warm. Nine times out of 10 the culprit is the snap-to-connect (STC) fitting on the back of the high-pressure oil pump that links the HPOP’s outlet to the branch tubes (which route oil into the stand-pipes, and then on to the oil rails in each head). As the branch tubes vibrate and flex, the STC fitting’s two-piece seal sees excessive wear, and eventually begins to leak oil. When the engine is cold and the oil is thick, it starts like normal, but when it’s warm (and the oil is thinner) it won’t fire off again. Adding insult to injury, the 6.0L’s HPOP is gear-driven at the back of the engine under its own cover, which means accessing the STC fitting calls for a healthy amount of labor. Long crank, no-start, surging throttle, rough idle, high IPR duty cycle readings, and poor performance are all symptoms of a high-pressure oil leak somewhere in the 6.0L’s HEUI system. Oftentimes the leak is traced back to a bad O-ring on a high-pressure stand pipe (shown), a dummy plug, a cracked branch tube, or the aforementioned STC fitting on the back of the HPOP. Many of the 6.0L’s drivability complaints are associated with sticking vanes in the Garrett GT3782VA turbocharger. This issue is common in trucks that spend the majority of their time idling, steady-state cruising, or parked in the driveway. When the moveable vanes (which vary the amount of exhaust gases directed across the turbine wheel) aren’t exercised regularly, they can fail to move at all. Turbo lag or zero high rpm power and a P0299 code stored in the PCM are telltale signs that it’s time to clean the turbo. Functionality of the electronically controlled variable geometry turbocharger is highly reliant on a working exhaust backpressure (EBP) sensor and a clean line spanning from the EBP sensor to the driver side exhaust manifold. If the sensor fails or the line plugs up, an inaccurate back pressure reading is sent to the PCM, a P0470 and/or P0299 code can be thrown, and the turbo’s VGT operation will be hindered. A seized unison ring is almost always the guilty party in a stuck turbo situation. The unison ring is the component that moves all of the variable vanes at once. When it hasn’t seen its full operating range in a while, rust and corrosion tends to form, causing it to cement itself in one position. In most cases, pulling the turbo and treating it to a thorough cleaning by way of a Scotch-Brite pad and a die grinder is all that’s required to get the VGT fully functional again. Perhaps the sneakiest killer of 6.0L performance is the fuel injection control module (FICM). Tasked with sending the precise voltage to each injector solenoid in order to fire it, the FICM has to operate at 48-volts at all times, including at key-on and while cranking the engine over. What newcomers and outsiders to the 6.0L world don’t know is that when the batteries become weaker and the engine gets harder and harder to start, the FICM is dying as well. As the driver side of the FICM fails, the FICM will gradually send lower and lower voltage the injectors’ way, all while performance suffers. It’s common to find hairline cracks in the 6.0L’s cast-iron cylinder heads (and the same goes for the 6.4L’s heads), but once they protrude into the valve seats it’s time to start over. A crack that spans into an exhaust valve seat is usually a hint that the engine saw elevated EGT on more than one occasion, and maybe even a fair amount of abuse. What components are used to enhance engine durability and reduce maintenance needs? Hydraulic roller followers are used to eliminate the need for valve lash adjustments, enhancing durability. What maintenance-friendly features are included in the engine design? The engine has externally accessible glow plugs and cartridge-style fuel and oil filters, making maintenance easier. What materials and construction techniques are used in the engine’s design? The engine utilizes a cast iron bedplate for rigidity and multi-layer stainless steel gaskets for durability. What kind of transmission is paired with the 6.0L engine? It features a 5-speed TorqShift™ automatic transmission, which improves acceleration, drivability, and low-end torque. What type of turbocharger does the 6.0L engine have? The 6.0L engine is equipped with a variable geometry turbocharger, designed to enhance responsiveness. Where can parts and accessories for diesel engines be purchased? Shop for all your vehicle needs, whether you’re looking for diesel engine parts, accessories, or other essentials to keep your ride running smoothly. Subscribe to our newsletter for updates on the latest in automotive parts, exclusive deals, and tips on maintaining your vehicle’s performance. Single Issues are available for those who want detailed guides and insights into specific vehicle maintenance and upgrades, including comprehensive articles on diesel engines. Merchandise ranges from branded apparel to tool kits, ensuring you’re equipped with everything you need for your automotive projects. Find everything in one place, whether you’re enhancing your diesel engine or diving into new automotive ventures. Our selection ensures you’re covered, no matter the task at hand. What type of products are available for certain vehicle brands? For brands like Ford and Lincoln, a variety of products, including both parts and accessories, are available to meet different automotive needs and preferences. Where can I find accessories for Lincoln vehicles? Accessories for Lincoln vehicles are available from dedicated suppliers that focus on providing products designed to enhance and customize your Lincoln. Where can I find parts for Ford vehicles? You can find the necessary components for Ford vehicles through specialized suppliers that offer a wide range of options tailored specifically for this brand. Total 2 Shares Share 0 Tweet 0 Pin it 2 Share 0
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