Cummins ISX Engine Specs, Reviews & Problems

February 5, 2020
Cummins ISX — History, Specs, Common Issues and Featured Products

Cummins has built a reputable name for itself over the decades, but how did it get to where it is today? This guide will discuss how Cummins started as a strong partnership that transformed into an impressive engine manufacturing company. Diesel Pro Power will take you through the Cummins ISX series’ specs, some of its most common issues and featured products. This guide applies to both original units or modern versions of the Cummins ISX Engine.

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.


Cummins Engine History

Clessie Cummins founded Cummins Engines in 1919 and partnered with J. Irwin Miller, a knowledgeable businessman well versed in business practices. By combining Cummins’ expertise in diesel technology and Miller’s business skills, they expanded the company to what it has become 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., 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 a hand 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 Engine History

The initial design of the Cummins ISX engine began in 1998. The original engine in the series was the N14, but over time as stricter Environmental Protection Agency (EPA) laws came into play, it became an obsolete line of engines. In 2002, the Cummins 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 ISX15 stands for “Interact System.” Since its launch, the Cummins ISX15 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 ISX15 became one of the first diesel engines to incorporate an exhaust gas recirculation (EGR) cooler system. This technology takes the engine’s exhaust and recirculates it back to the intake chamber, reducing NOx particles. The ventilated exhaust is then able to lower the combustion chamber temperature.

The Cummins ISX then began featuring the selective catalytic reduction (SCR) system in 2006. It injects urea, an active element in diesel exhaust fluid (DEF), into the exhaust. Ammonia in the urea then 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). This 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.

At one point, the ISX15 had a dual overhead camshaft design. One cam would activate the injectors, and the second initiated the valve train. This dual camshaft design was a complicated injection system that was cam actuated to form injection pressure and deliver fuel. However, it didn’t last into subsequent ISX versions after 2010.

The Cummins ISX engine underwent a redesign to meet the 2010 EPA standards through developments in 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 can be distributed through the tubing to the rail system for storage under extreme pressures— about 35,000 PSI or higher.

This version of the ISX15 relies on an engine control module (ECM) to monitor its timing and pressure. The ECM can activate each fuel injector up to five times per combustion cycle, while the single camshaft improvement creates a better fuel economy and reduces emissions to stay parallel with EPA standards.

By 2013, the Cummins ISX gained onboard 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 ISX15, its Cummins specs 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 Cummins ISX15 engine now comes complete with several prominent features that make it one of the most sought-after solution fulfilling engines on the market. Compared to the original N14 series from the late 1990s, the ISX15 now delivers an exceptional line of components that have been engineered and upgraded each year, including:

Cooled exhaust gas recirculation: If your Cummins ISX 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 Cummins ISX’s advanced crankcase ventilation only needs replacement after every third or fourth oil change, allowing for more prolonged operation and more use.

Cummins Intebrake™: The Intebrake™ can reach up to 600 braking HP, which helps control the machine and reduce brake wear.

Dual overhead camshafts: As noted above, if your ISX15 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 Cummins ISX fuel pump 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 ISX15 engine can run up to 15,000 miles between oil and filter changes.

Mid-stop cylinder liners: Cylinder liners within the ISX15 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 of the ISX engine 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, always refer to your manufacturer’s manual first. Address any problems immediately to avoid more severe damage. Here are some tips to keep in mind before making engine repairs to your ISX engine:

– Check the dual or single overhead cams.

– Inspect the spring-loaded cam gear and release the tension before unloading.

– Set the idol gear.

– 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 ISX15? Does it have an EGR system?

When it comes to common ISX engine 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’re operating to understand what troubleshooting and repairs are necessary.

For example, ISX 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 ISX15 failures and can be 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 a leaking EGR valve which 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.


The rocker arms within your ISX engine 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.

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 easily by simply changing the oil filter. If the problem seems to improve, you will then need to retime the ISX engine using a dial indicator. It’s a sensitive procedure, so you may need to rely on 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 ISX engine is to conduct preventative and regular maintenance according to your manufacturer’s manual.


Why the Cummins ISX15 Engine 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. Whether you’re a yacht or a workboat owner, the ISX15 may be the ideal provision for you. Several of the ISX15 engine’s featured products include:

Cylinder head with valves: When a cylinder head is remanufactured to advanced conditions, it will function 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.

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. Cummins injectors also include new external O-rings and filters.

Inframe engine rebuild kit with re-ring and fewer pistons: The ISX15 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 ISX engine has worn camshafts, they can reduce horsepower and affect the valve timing. The valve camshaft involves precise remanufacturing.

ISX15 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 ISX15 series’ components, even into 2020, where their latest version already meets 2021 greenhouse gas regulations and fuel economy standards.

The ISX engine also has unmatched fuel economy, emissions, performance and cooling systems:

Fuel economy: The ISX15 has efficient water and fuel pumps which deliver more usable horsepower to your operations. Cummins ISX fuel and water pumps use technology to generate optimized combustions and fewer regenerations of the aftertreatment system. The ISX15 undergoes better fuel economy advancements with each new version.

Emissions: Current ISX engines meet EPA standards along with DOT regulations because of onboard diagnostics that look at optimal emission performances.

Performance: The ISX15 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 ISX15 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 Cummins 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.

Follow by Email