The ISX engine by Cummins is one of the most popular diesel engines on the road today. The first ISX was produced in 1998, as a response to the EPA's tighter emissions restrictions. It soon replaced the N14, the other workhorse engine produced by Cummins. Throughout its production history, Cummins has made various changes to the engine in order to keep up with the increasing restrictions, changing from a dual-cam to a single-cam and adding a cooled EGR system to reduce NOx emissions.
Despite its popularity, it does have its problems, like any other engine. Some of these issues depend on which version of the ISX you're running—obviously if you're running a pre-2002 ISX without an EGR then you won't be experiencing issues with the EGR. Here we discuss some of the problems you might run into with your ISX.
Performance: The ISX has a massive range of horsepower, depending on which version suits your application. With a max 2,050 lb.-ft. Of peak torque, the engine’s SmartTorque adds 200 lb.-ft. Of extra torque when needed. You can tailor the unit’s performance to your specific needs. When you do the 300-ft lbs on the head bolts, let it sit overnight 24 hours. Then the next day, re-torque to 300 ft lbs again a second time. Most of the bolts will go another 1/4 - 1/2 turn. After that, you should take them the other 90 degrees for the final setting like the book says. The latest from Cummins Inc. As leaders in battery, fuel cell, and hydrogen-production technologies, we’re steering the way to a brighter tomorrow.
EGR Issues
As we mentioned, the EGR system was a newer addition to the ISX. Like any other engine with an EGR, the system can cause some problems. On the ISX, it most likely has to do with a leak in the EGR valve.
This is a difficult problem to diagnose, but monitoring the coolant consumption can help. If you notice that it's using a larger amount of coolant than normal, it's probably worth investigating further. Similarly, there might be a white residue left behind from the burnt coolant. This is another telltale sign of a leak. This kind of problem is more common on older style EGR systems, as many newer ones have tried to address and fix the issue.
Flattened Camshafts in the ISX
The ISX also has a history of camshaft issues. We discussed this briefly in Cummins ISX Engine Spotlight. In short, an ISX camshaft can flatten out. This is not because of an issue with the camshaft itself, but with the rocker arms. According to Cummins, there was a production of rocker arms that prevented proper oil flow, starving the components. These bad rocker arms stick and smack the camshaft, causing the lobes to flatten.
You can fix this failure by replacing both the affected camshaft and the rockers. If you don't correctly diagnose the problem and leave the faulty rockers, then the same thing will happen to your new camshaft. Apart from performance issues caused by a worn camshaft cluing you in to a camshaft problem, there aren't any particular symptoms to watch for that indicate whether or not you have these rockers.
Camshaft Timing Wedge Issue
This issue is usually found after a camshaft repair or overhaul, when the timing might be affected. When the engine was assembled, it was timed according to a certain procedure using timing wedges. This turned out to be kind of a crude way to time an engine, and Cummins found that through either sloppy procedures or worn tooling, the wedges had a tendency to wear. This changed the timing of the camshaft.
The system itself is very particular, and the change in timing can upset the balance in the engine. If fuel is injected even slightly late because of the camshaft timing, it would create conditions that allowed for the creation of soot. The soot would then contaminate the oil, creating buildup in the oil filter. This buildup causes oil pressure to drop.
One way to help diagnose this issue is to change the oil filter. If the issue seems fixed, then the engine needs to be retimed with a dial indicator. This is a fairly involved process and still requires the use of timing wedges. It's a very sensitive procedure that should be handled with care. It also might be diagnosable if you notice, or a customer calls and complains about, reduced oil pressure after new parts were installed or an overhaul was performed.
If you notice any signs of these issues, you'll want to address them right away to avoid further damage to your ISX engine. As we said, depending on your particular ISX, some of these issues might not affect your engine, so it's helpful to know what you have a single- or dual-cam ISX, as well as whether or not it has an EGR system. These can help you more carefully diagnose problems with your engine.
Do you still have questions about your ISX? You can speak with one of our certified techs at 844-304-7688, or you can request a quote online.
Cummins has built a reputable name for itself over the decades, but how did it get to where it is today? In this guide, we’ll discuss how Cummins started as a strong partnership, then transformed into an impressive engine manufacturing company. Diesel Pro Power will take you through the ISX series’ specs, common issues and featured products, whether you have one of the original units or a modern version.
When you know the ins and outs of your engine system, you can better prepare your marine or generator applications to make functional repairs when necessary.
A Brief History
Clessie Cummins founded Cummins Engines in 1919 and partnered with J. Irwin Miller, a knowledgeable man in business practices. By combining Cummins’ expertise in diesel and Miller’s business skills, they were able to expand the company to how we know it today. Through the decades, the Cummins brand has integrated itself into a multitude of areas within the diesel industry.
For example, in 1973, Cummins bought Holset Engineering Co., which was a company focused on engineering engine parts. Cummins also acquired Onan in 1986, a company that manufactured generator sets. The name was later changed to Cummins Power Systems.
In 1989, Cummins began working with Dodge Ram, and the name soon changed to Cummins Emissions Solutions.
Cummins is an engineering company that has its foot in multiple critical areas of the market. With growing expertise in engine manufacturing, emissions solutions, gensets and parts engineering, Cummins excels in manufacturing products and solutions for marine engines and generators.
Cummins ISX History
The initial design of the Cummins ISX began in 1998. The original engine in the series was the N14, but over time, it became an obsolete line of engines, as stricter Environmental Protection Agency (EPA) laws came into play.
In 2002, the ISX15, also known as the “Signature” series, started production. It upheld its name because it had an innovative fuel system called the “Interact System.” The “IS” in ISX stands for “Interact System.”
Since its launch, the ISX has been the core of Cummins’ diesel engine fleet. Not only has it advanced with quicker processing, but it has also increased fuel efficiency since its debut.
In 2002, the ISX became one of the first diesel engines to incorporate an exhaust gas recirculation (EGR) cooler system. The technology takes the engine’s exhaust and recirculates it back to the intake chamber, reducing NOx particles. The ventilated exhaust lowers the combustion chamber temperature.
The ISX started featuring the selective catalytic reduction (SCR) system in 2006. It injects urea, which is an active element in diesel exhaust fluid (DEF), into the exhaust. Ammonia in the urea chemically reacts with the NOx particles and converts them into nitrogen and water inside the catalytic converter. DEF reaches high temperatures in the holding tank, then pumps into the injector and decomposition tube, causing it to react to the NOx in the exhaust.
New advancements in emissions technology emerged when Cummins introduced the diesel particulate filter (DPF). The system captures the exhaust produced from the combustion chamber and neutralizes the soot through oxidation. The oxidized ash transforms into dust. Then, it’s regenerated through the turbo in a process known as regeneration.
The ISX had a dual overhead camshaft design. One cam activated the injectors, and the second initiated the valve train. This complicated injection system was cam actuated to form injection pressure and deliver fuel. However, it didn’t last into the next ISX versions after 2010.
The Cummins engine underwent a redesign to meet the 2010 EPA standards through developments in the emissions technology. The company’s advancements focused on a single overhead camshaft instead of a dual solution. They also innovated the common rail fuel system, which eradicated the need for an injector camshaft to generate pressurized fuel.
In the common rail fuel system, diesel fuel becomes pressurized via multiple piston pumps. Then, it’s distributed through the tubing to the rail system for storage under extreme pressures— about 35,000 PSI or higher.
This version of the ISX relies on an engine control module (ECM) to monitor the timing and pressure. The ECM can activate each fuel injector up to five times per combustion cycle. The single camshaft improvement creates a better fuel economy and reduces emissions to stay parallel with EPA standards.
By 2013, the ISX gained on-board diagnostics to track the engine’s emissions. This change increased fuel efficiency compared to previous versions. Each year, Cummins continues to update the ISX15 to meet EPA standards.
Cummins ISX Specs
A Cummins ISX engine is an Inline-6 diesel with a duel-fuel configuration — meaning it can run on diesel or natural gas — although, diesel is the most common. If you’re in the market for an ISX, its specification log includes:
– 400-600 hp
– 2,050 lb.-ft. maximum peak torque
– 2,000-2,100 RPM engine speed
– 1,000 lb.-ft. clutch engagement torque
– Six cylinders
– 14 gallons of oil capacity
– 15-liter design
– 3,093 lbs. system weight
– 3,021 lbs. dry weight
– 72 lb. aftertreatment
Throughout each improved generation, the ISX engine now has several prominent features that make it one of the most sought-after solutions. Compared to the original N14 series back in the late 1990s, the ISX now delivers an exceptional line of components that have been engineered and upgraded each year, including:
Cooled exhaust gas recirculation:If your engine was made after 2002, it has an EGR system. Recirculation within the engine lowers the combustion temperatures, which reduces optimized MPG and emissions.
Crankcase ventilation system:The ISX’s advanced crankcase ventilation only needs replacement after every third or fourth oil change, allowing you to operate for longer.
Cummins Intebrake™: The Intebrake™ can reach up to 600 braking HP, which helps control the machine and reduce brake wear.
Dual overhead camshafts: If your ISX was manufactured before 2010, it has a dual camshaft system. The first cam creates high-pressure fuel injection for clean power while the second has a set of lobes to operate the integrated engine brake. The second set of camshafts also moves the intake and exhaust valves. With a high-pressure fuel injection system, a marine engine can produce complete combustion.
High-pressure fuel injection system:The high-pressure system forms a clean and complete combustion phase.
Integrated electronic controls: Engines produced after 2010 rely on an ECM. The engine’s ECM controls the aftertreatment. It also synchronizes interactions between the ABS, transmission, engine brake, cooling fan and other components.
Low maintenance: An ISX engine can run up to 15,000 miles between oil and filter changes.
Mid-stop cylinder liners: Cylinder liners within the ISX have a strong design to allow for variations in coolant chemistry.
Particulate filter:An ISX engine has a fully integrated particulate filter for uncompromised performance by reducing particulate matter.
Single overhead camshaft: Versions made after 2010 have a single camshaft system with a common rail fuel operation that relies on piston pumps to inject diesel.
Variable geometry turbocharger:The turbocharger has a sliding nozzle to boost durability and reliability. Its electric actuation enhances its responses and control for adjustment. The component also delivers a definite increase at any RPM.
Cummins has mastered the engineering process by integrating each possible solution into one unit.
Common Cummins ISX Issues
When you find your ISX engine is experiencing issues, refer to your manufacturer’s manual. Address any problems right away to avoid more severe damage. Here are some tips to keep in mind before making engine repairs:
– Check the dual or single overhead cams.
– Inspect the spring-loaded cam gear and release the tension before unloading.
– Set the idol gear.
Cummins Isx Head Bolt Torque Sequence
– Use a puller tool for the front and back seal.
– Use heavy-duty cams.
– Work with specified parts for ISX engines.
Do you have a single or dual cam ISX? Does it have an EGR system?
When it comes to common ISX issues, some problems may not affect your engine, depending on the year it was made. It’s important to know what version of the marine engine you operate to understand what troubleshooting and repairs are necessary.
For example, engines engineered before 2002 will experience more problems with EGR compared to modern types. In 2008, Cummins began noticing the SCR system experienced failing revolving parts, interfering with the engine’s horsepower. Clogged inlets came about in 2010 when recirculation was occurring, also affecting HP.
Depending on the version you have, common Cummins ISX engine problems involve the turbocharger, EGR, camshafts and timing wedge:
Variable Geometry Turbocharger
The turbocharger is one of the most notorious ISX failures and is expensive to fix. While they are ideal for direct throttle response, VGTs often experience a buildup of carbon, soot, rust and other contaminants. You may feel no response from the engine or an extreme retort at low RPMs. The best fix is to clean the exhaust side of the VGT, replace its parts or swap it for a fixed unit.
EGR System
Another common problem is an EGR valve that leaks. It can cause black smoke and power loss to your ISX engine. Although it’s tricky to diagnose, you can monitor the unit’s coolant to see if leaks are present. If you’re using more coolant than usual, it can be an indication of a leak. Another sign is if you notice white residue from the burnt coolant. EGR system issues are more common in older versions of ISX engines.
Isx Head Torque
Camshaft
Rocker arms within your ISX may be damaging the camshafts, which causes an improper amount of oil to pass. When the rockers hit the camshaft lobes, it flattens them. This deprivation causes your marine or generator application to experience performance issues. You can replace both the camshaft and rockers to deter the problem. Swapping rocker arms for new ones is vital. Otherwise, they will flatten the new camshaft as well.
Isx Head Torque
Timing Wedge
Problems with a timing wedge often happen after you repair or overhaul the camshaft. Wedges have a tendency to wear, which inadvertently alters the camshaft timing, therefore, wrecking the engine’s balance. Fuel injection that occurs at the wrong time can affect the entire system. If it’s too late, it can create soot, contaminating the oil. Over time, a buildup of contamination can form in the oil filter, resulting in a drop in oil pressure.
Avoid the timing wedge issue by changing the oil filter. If the problem seems to improve, you need to retime the ISX engine using a dial indicator. It’s a sensitive procedure, so you may need to rely on the professionals to take over.
Certain ISX engines experience more problems than others, but each issue has a set of simple troubleshooting procedures. One of the best ways to eliminate problems with your Cummins is to conduct preventative and regular maintenance according to your manufacturer’s manual.
Why the Cummins ISX May Be Ideal for You
The Cummins ISX trumps other engine solutions by living up to EPA emission standards and having an advanced fuel economy. The ISX may be the ideal provision, whether you’re a yacht or a workboat owner. Several of the engine’s featured products include:
Cylinder head with valves: With a cylinder head remanufactured to advanced conditions, it functions like new. The new internal components are tested for air decay and are also wet tested. It has chased threads, and mechanics weld any cracks to avoid leaks.
Inframe engine rebuild kit:The rebuild kit includes new parts. The pistons are made from heat-treated steel and have a modern closed-skirt design. With induction-hardened cylinder liners, it delivers improved wear resistance. The rod bearings are made from bi-metal for better strength, durability and fitment.
Isx Fuel Pump Head Torque
Fuel injector: A remanufactured ISX fuel injector has new parts ranging from the spill valve, shim and NOP spring to screws and the actuator assembly. It also includes new external O-rings and filters.
Inframe engine rebuild kit with re-ring and fewer pistons: The ISX has an inframe rebuild option for when your pistons are in good shape. It has oil control rings made with precise tangential tension for ideal control, and the gaskets are made with premium materials.
Valve camshaft:If your engine has worn camshafts, they can reduce the amount of horsepower and affect the valve timing. The valve camshaft involves precise remanufacturing.
ISX variable speed propulsion engines are perfect for recreational, commercial and government marine applications. Cummins strives to upgrade and improve each component in their ISX engine series to deliver superior dependability and performance. The marine engine has an exceptional fuel economy compared to other big-bore engines and outstanding braking features.
Cummins continues to expand the X15 series’ components, even into 2020, where their latest version already meets 2021 greenhouse gas regulations and fuel economy standards.
The ISX also has unmatched fuel economy, emissions, performance and cooling systems:
Fuel economy: The ISX has efficient water and fuel pumps which deliver more usable horsepower to your operations. Cummins uses technology to generate optimized combustions and fewer regenerations of the aftertreatment system. The ISX undergoes better fuel economy advancements with each new version.
Emissions: Current ISX engines meet EPA standards along with DOT regulations because of on-board diagnostics that look at optimal emission performances.
Performance: The ISX has a massive range of horsepower, depending on which version suits your application. With a max 2,050 lb.-ft. of peak torque, the engine’s SmartTorque adds 200 lb.-ft. of extra torque when needed. You can tailor the unit’s performance to your specific needs.
Cooling system: The cooling system underwent a size reduction without losing power to increase aerodynamics. It also reduces losses seen in the alternator’s performance and other water pumps. A smaller cooling solution creates an open room, forming cooled air around the engine.
Cummins also continues to improve the combustion chamber to result in fewer active regenerations of the aftertreatment. The ISX has advanced components and featured products to support your marine and generator applications.
Diesel Pro Power Has What You Need
Diesel Pro Power has a vast inventory of ISX marine engine components, including freshwater parts and Cummins ISX cables for when you experience problems with your system. With more than 15,000 satisfied customers, we provide 24-hour worldwide shipping through our easy-to-use website. Our specialists deliver complete solutions for your specific applications and needs by working with you one-on-one.
Browse our ISX engine parts or reach out to our customer care team by calling 1-877-597-1353. We deliver solutions with precision to your specific demands.