Cummins ISX15
Used Cummins ISX15 Engine for Sale
The ISX15 is the 15-liter Cummins that powered a large share of Class 8 trucks in the 2010s, and it came in very different versions by emissions year. Send us your ESN, CPL and ECM type and we search supplier sources nationwide for a matching engine.
Cummins ISX15 at a glance
- Displacement
- 14.9 L (about 912 cu in)
- Configuration
- Inline 6-cylinder
- Typical horsepower range
- About 400 to 600 hp depending on rating
- Production era
- ISX15 name used from the 2010 emissions engine until the X15 took over for 2017; earlier ISX engines date back to the late 1990s
- Emissions / aftertreatment
- 2010-on: cooled EGR, VGT turbo, DPF and SCR (DEF). Earlier ISX: EGR (2002-on) and DPF (2007-on), no SCR
- Common applications
- Class 8 linehaul, heavy haul and vocational trucks across most North American makes
Identification
How to identify your ISX15
Read us the ESN and CPL from the Cummins dataplate on the engine. The ESN is also stored in the ECM and can be read with diagnostic software if the label is gone.
Tell us which ECM the engine uses. The ECM part family (CM870, CM871, CM2250 or CM2350) is printed on the module itself and is one of the fastest ways to place an ISX in the right emissions generation.
- ESN and CPL from the dataplate
- ECM type printed on the module (CM870, CM871, CM2250, CM2350)
- Does the truck have a DEF tank? (yes points to 2010-or-later)
- Truck year, make, model, VIN and horsepower rating
01ISX generations by ECM: CM870, CM871, CM2250
Buyers often say ISX and ISX15 interchangeably, but the ECM generation matters more than the name. As a general guide: CM870 engines are the 2002-2006 EGR ISX; CM871 engines are the 2007-2009 ISX with a DPF; CM2250 engines are the 2010-and-later ISX15 with SCR and DEF. Later ISX15 engines built for GHG14 used an updated ECM platform.
Each generation uses a different harness, sensor set and aftertreatment, so a CM871 engine is not a direct replacement for a CM2250 truck, and the reverse is also true. Quote the same generation your truck was built with.
02Dual overhead cam ISX vs single cam ISX15
Pre-2010 ISX engines use a dual overhead cam design, with one camshaft for the valves and a second driving the fuel injectors (HPI-TP fuel system). The 2010 ISX15 moved to a single overhead cam with the XPI high-pressure common-rail fuel system.
That change affects the cylinder head, fuel system, injectors and service parts. It is another reason a 2010-on ISX15 and a 2007-2009 ISX are not interchangeable without a full conversion.
03EGR, VGT and DPF parts to ask about
From the 2002 EGR engines onward, the ISX relies on a VGT turbocharger, EGR valve and EGR cooler. On a used engine these are high-value, high-wear parts, so it matters whether they are included and whether they came off the same engine.
If you are replacing an engine because of an EGR cooler failure or coolant in the oil, tell us. It helps the supplier understand which replacement parts you need and whether you want the engine dressed or long-block.
04ISX15 vs X15 replacement
Because the X15 superseded the ISX15, some buyers ask whether to move up. An X15 in an ISX15 chassis needs ECM, wiring and aftertreatment work. For most repair jobs the practical choice is a used ISX15 with the same CPL family and ECM.
Before you buy
Questions to ask about a used ISX15
- Which ECM does this engine have (CM870, CM871, CM2250 or CM2350), and is it included?
- Does the CPL match my truck, or is it a different rating or build?
- Is the mileage documented with an ECM report or donor truck VIN?
- Is an oil analysis or blow-by check available?
- Is there a running video showing a cold start and idle?
- Are the VGT turbo, EGR valve and EGR cooler included?
- Does it come with the engine harness, and is any aftertreatment included?
- What are the core requirements, and does a cracked block or head affect core credit?
FAQ
Cummins ISX15 questions
What is the difference between ISX and ISX15?
ISX15 is the name Cummins used for the 2010-and-later 15-liter engine with SCR and DEF. Older ISX engines (2002-2009) use different ECMs, a dual overhead cam layout and no SCR. Your ECM type and ESN tell us which one you have.
Can I put a 2010 ISX15 in a 2007 truck?
Not as a simple swap. The 2010 engine uses a different ECM, fuel system and aftertreatment with DEF. It is usually far easier to replace a 2007-2009 ISX with the same generation.
How do I tell if my ISX is a CM871 or CM2250?
Look at the label on the ECM itself. A DEF tank on the truck is also a strong sign of a 2010-or-later CM2250 engine.
Do you have ISX15 engines with the turbo included?
We do not hold inventory. We search supplier sources for your engine, and each quote states whether the turbo, ECM, harness and EGR parts are included.
Is a used ISX15 ECM programmed to my truck?
Generally no. A used ECM usually needs to be reprogrammed with your VIN and truck parameters by a shop with Cummins software. Ask your shop to plan for that.
What does the CPL tell you on an ISX15?
The CPL lists the build: turbo, fuel system, rating range, flywheel housing and accessory layout. Matching CPL avoids surprises with brackets, plumbing and calibration.
More Cummins engines
Trucks that may use the ISX15
Ready when you are
Looking for a Cummins ISX15? Send the serial number.
Have your engine serial number, CPL and VIN handy. If you don't, we'll help you find them.
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