Remanufactured CAT C15 15.2L (928 ci) Engine For Sale
1999–2010 — 435–625 hp | 1,550–2,050 lb-ft
The Caterpillar C15 is one of the most iconic heavy-duty diesel engines ever produced. Introduced in 1999 as the successor to the legendary 3406E, the C15 quickly became the engine of choice for owner...
Starting from $8,000 – $16,000 — 1-Year Unlimited Mileage Warranty
CAT C15 Technical Specifications
About the Caterpillar C15 Engine
The Caterpillar C15 is one of the most iconic heavy-duty diesel engines ever produced. Introduced in 1999 as the successor to the legendary 3406E, the C15 quickly became the engine of choice for owner-operators who demanded maximum power and reliability. The pre-ACERT 6NZ model (1999–2003) is widely considered the most desirable version, offering 435–550 hp with a simple, proven design that avoids the complexity of later emissions equipment. In 2004, Caterpillar introduced ACERT (Advanced Combustion Emissions Reduction Technology) in the BXS and later MXS variants, which used twin turbochargers and advanced fuel injection to meet EPA emissions standards. The C15 ACERT offered ratings up to 625 hp, making it one of the most powerful Class 8 engines available. Although Caterpillar exited the on-highway truck engine market in 2010, the C15 remains one of the most sought-after engines in the used truck market, with the 6NZ commanding premium prices for its simplicity and proven million-mile durability.
CAT C15 Strengths
- The 6NZ (pre-ACERT) is widely regarded as one of the best diesel engines ever made
- Massive power output — up to 625 hp in ACERT configuration
- Proven million-mile durability with proper maintenance intervals
- Strong aftermarket support with abundant parts availability
- Excellent resale value — 6NZ-powered trucks command premium prices
- Robust bottom end with forged steel crankshaft and connecting rods
Common CAT C15 Issues (Addressed in Our Remanufactured Engines)
- ACERT models (BXS/MXS) can experience twin turbo failures and boost leaks
- Injector o-ring failures on high-mileage engines cause fuel dilution in oil
- Oil pan rail cracking on early 5EK serial number blocks (inherited from 3406E)
- ACERT regeneration system issues on 2007+ models with DPF
- Coolant leaks from water pump and thermostat housing gaskets
- Cam and lifter wear on high-mileage engines requires inspection during rebuild
Vehicles with the CAT C15
CAT C15 Buying Guide
When purchasing a remanufactured Caterpillar C15, the engine serial number prefix is the most critical identifier. The 6NZ prefix (pre-ACERT, 1999–2003) is the most sought-after and commands the highest prices due to its simplicity and reliability. The BXS prefix (early ACERT, 2004–2006) introduced twin turbos and is a solid choice for those who want more power. The MXS prefix (late ACERT, 2007–2010) offers the highest horsepower ratings but includes DPF emissions equipment. Always verify the horsepower rating matches your truck's ECM programming. A quality remanufactured C15 should include new injectors, rebuilt turbo(s), new cam followers, and a complete gasket set.
Frequently Asked Questions — CAT C15
How much does a remanufactured Caterpillar C15 engine cost?
A remanufactured Caterpillar C15 engine typically costs between $8,000 and $16,000 depending on the serial number prefix (6NZ, BXS, or MXS), horsepower rating, and emissions configuration. The pre-ACERT 6NZ models are the most popular and often at the higher end due to demand. All our CAT C15 engines are fully dyno tested and backed by our comprehensive warranty. Call (631) 991-7700 for an exact quote.
What is the best CAT C15 engine?
The Caterpillar C15 6NZ (1999–2003) is widely considered the best version. It offers 435–550 hp without the complexity of ACERT emissions equipment, making it simpler to maintain and more reliable long-term. The 6NZ is the most sought-after serial number prefix in the used truck market. However, if you need maximum power (up to 625 hp), the ACERT BXS or MXS models are excellent choices.
What are common Caterpillar C15 problems?
Common C15 issues include injector o-ring failures (causing fuel in oil), ACERT twin turbo failures on BXS/MXS models, coolant leaks from water pump gaskets, and cam/lifter wear on high-mileage engines. The pre-ACERT 6NZ has fewer known issues overall. Our remanufactured C15 engines address all known problems with updated components and thorough testing.
What trucks use the Caterpillar C15 engine?
The Caterpillar C15 was installed in most major Class 8 trucks from 1999 to 2010, including Peterbilt 379/389/386, Kenworth W900/T800/T600, Freightliner Classic XL/Columbia, International 9400i, Western Star 4900, and select Volvo VNL configurations. It was the dominant engine choice for owner-operators during its production run.
How many miles can a CAT C15 last?
A well-maintained Caterpillar C15 can last 750,000 to over 1,000,000 miles before requiring a major overhaul. The 6NZ variant is particularly known for exceptional longevity. Key maintenance items include regular oil changes (15,000–25,000 mile intervals), coolant system service, valve adjustments, and injector replacement at recommended intervals.
What is the difference between CAT C15 6NZ and ACERT?
The 6NZ (1999–2003) is the pre-ACERT version with a single turbocharger and simpler emissions system — no EGR or DPF. The ACERT models (BXS 2004–2006, MXS 2007–2010) introduced twin turbochargers, advanced fuel injection, and emissions equipment (EGR and later DPF) to meet EPA standards. The 6NZ is simpler and more reliable, while ACERT models offer higher horsepower ratings up to 625 hp.
Caterpillar Troubleshooting Guides
Caterpillar C15 Problems
ACERT vs pre-ACERT issues, injector failures, head gaskets, and oil pressure problems.
Read Guide →Diesel Engine Cost Guide
Complete pricing for remanufactured Caterpillar engines by model.
Read Guide →Reman vs Rebuilt Engines
Which option is right for your CAT? Compare quality, cost, and warranty.
Read Guide →Installation Guide
Step-by-step guide for installing your remanufactured engine.
Read Guide →