Caterpillar C15 Cat Engine for Sale | 15.2L Inline-6 Turbocharged Diesel for Class 8 Trucks

$12,999.00

Product Overview & Specifications

In Stock, Pre-ACERT 6NZ and ACERT (MXS / SDP / 6TZ) Variants Available
Free Shipping to All 50 States via Crated Freight, 7 to 14 Business Days
Variant Confirmed (Pre-ACERT 6NZ vs ACERT MXS / SDP / 6TZ)
ECM Serial Number Documented for Cat Connect Compatibility
Turbocharger and Air-to-Air Aftercooler Inspected
Top-End Condition Inspected (Heads, Injectors, Rocker Arms)
MEUI Injector Operation Verified Where Possible
Donor Truck Documented (Freightliner, Kenworth, Peterbilt, Mack, International, Western Star)
100% Inspection Before Every Order Ships
15 Day Replacement Warranty on Internal Defects

100% Fitment Assistance

15 Days Replacement Warranty

Free & Fast Shipping

Category: Engine

Description
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Used C15 Cat Engine for Sale

Renowned for its durability and performance, the Caterpillar C15 engine is highly sought after across multiple industries. The C15 Engine for sale at is a powerful Class 8 truck diesel with proven reliability. Though used, this motor is the perfect solution for your over-the-road trucking, vocational, and commercial needs.

The Caterpillar C15 engine is a powerhouse, delivering exceptional performance in heavy-duty applications. From Class 8 trucks to industrial machinery, the C15 engine for sale is designed to meet the rigorous demands of various operational environments.

The C15 Family Tree, Pre-ACERT vs ACERT

The C15 was offered in two main generations across its production life:

After 2007, Caterpillar exited the on-highway truck engine market in North America, making the late ACERT C15 variants the last “Cat Truck Engine” available new (until the modern CT-15 / Cat Industrial C15 platform). This historical position adds collector and restoration value to documented C15 cores.

Features of the C15 Engine

MEUI Fuel System: Fuel injection is performed by MEUI (Mechanically Actuated, Electronically Controlled Unit Injection), which combines mechanical actuation with electronic control of injection timing and quantity. This delivers precise fuel control for performance and economy.

Turbocharging and Aftercooling: The C15 features a turbocharger and air-to-air aftercooler for high-efficiency air intake, which improves power delivery and fuel consumption while keeping intake air temperatures controlled.

Robust Design: Built with a cast iron block, forged steel crankshaft, and high-quality components designed to withstand the abuse of Class 8 trucking duty cycles.

Overhead Valve (OHV) Configuration: OHV with 4 valves per cylinder (2 intake, 2 exhaust) provides good breathing while maintaining the simpler service architecture of OHV vs OHC engines.

ACERT Technology: ACERT (Advanced Combustion Emission Reduction Technologies) on 2004-2007 variants reduces particulate matter and NOx emissions through optimized combustion timing, VVA, and EGR.

Exhaust Gas Recirculation (EGR): On ACERT variants, EGR reduces nitrogen oxide (NOx) emissions to meet 2004-2007 EPA standards.

Electronic Control Module (ECM): Caterpillar’s ECM regulates fuel injection, air management, EGR (on ACERT), and VVA (on ACERT). The ECM also provides Cat ET diagnostic capability and stores fault history.

High Torque at Low RPM: The C15 produces peak torque of 2,050 lb-ft at low rpm, providing excellent low-end pulling power for hauling heavy gross combination weight (GCW) loads.

Variable Valve Actuation (VVA): ACERT variants use VVA to optimize valve timing for emissions and efficiency across the rpm range.

Engineered Cooling System: The C15 cooling system is sized for sustained heavy-duty operation, keeping engine temperatures stable under maximum-load operation.

Models and Variants

We offer several models of the C15 Cat engine for sale, including pre-ACERT 6NZ and ACERT (MXS, SDP, 6TZ) variants. These engines are available in various configurations to ensure they meet your particular requirements. Tell us your truck year, donor truck (Freightliner Classic XL, Kenworth T800, Peterbilt 389, etc.), and ECM compatibility requirements, and we’ll match the appropriate variant.

Common C15 Applications

Class 8 Heavy-Duty Trucks: Freightliner Classic XL, Freightliner Coronado, Kenworth T800, Kenworth W900, Peterbilt 379, Peterbilt 389, Peterbilt 365, Mack (Caterpillar engine option), International, Western Star 4900, Western Star 5900

Marine Propulsion: Commercial vessels using C15 marine variants for tug and workboat applications

Industrial / Power Generation: C15-based generator sets and stationary power applications

Mining and Construction: Heavy haul mining trucks and construction equipment

Signs You Need a Replacement C15

Loss of compression on one or more cylinders (low oil pressure on cold start, blue smoke, oil consumption)

MEUI injector failure (rough running, high EGR fault codes, smoke)

Turbocharger failure (boost drop, blue oil smoke, whistle / surge sounds)

Cylinder head crack (coolant in oil, white smoke, overheating)

Connecting rod or main bearing knock under load

ACERT-specific: VVA solenoid wear, EGR cooler failure (on MXS / SDP / 6TZ variants)

Donor truck has been totaled and the C15 is being moved to a different chassis

High-mileage repower of an aging Class 8 truck

Condition and Quality Assurance

Our inventory includes high-quality, thoroughly inspected used C15 engines for sale. Each engine undergoes rigorous testing to ensure it meets our stringent standards for performance and reliability. We pride ourselves on providing engines that are not only affordable but also dependable.

aspiration	Turbocharged with air-to-air aftercooler
bore-x-stroke	5.4 in x 6.75 in
compression-ratio	16.0:1
configuration	Inline-6
cooling-system	Liquid cooled
fuel-system	Electronically Controlled Unit Injection), MEUI (Mechanically Actuated
intake	Turbocharged with intercooler / aftercooler
operating-speed	1, 100 rpm, 800 to 2
power-ratings	354 to 433 bkW
valvetrain	4 valves per cylinder, OHV
horsepower	435 to 625 hp
torque	050 lb-ft, 2
displacement	15.2 liters (928 cubic inches)
weight	090 lbs, 3
block-material	Cast Iron
head-material	Aluminum
acert-technology	Yes (on 2004-2007 MXS / SDP / 6TZ variants)
egr	Yes (on ACERT variants only)
vva	Yes (on ACERT variants only)

FAQs

Availability of the C15 for sale?

Yes, we have multiple Caterpillar C15 engines in stock, both pre-ACERT 6NZ (1999-2003) and ACERT (MXS / SDP / 6TZ, 2004-2007) variants. Sourced from Freightliner, Kenworth, Peterbilt, Mack, International, and Western Star Class 8 truck donors.

What’s the price of the C15?

$12,999.00 for this listing (SKU vaz85). Genuine Caterpillar reman C15 engines run $25,000 to $42,000. Independent reman runs $18,000 to $28,000. Our used C15 with full inspection and variant identification represents excellent value for Class 8 truck repower projects.

What’s the difference between pre-ACERT 6NZ and ACERT MXS / SDP / 6TZ?

Pre-ACERT 6NZ (1999-2003) has no EGR, simpler emissions hardware, and is highly tunable. Owner-operators love the 6NZ for its raw character and tunability potential (often 800+ hp with appropriate modifications). ACERT MXS / SDP / 6TZ (2004-2007) added Variable Valve Actuation (VVA) and Exhaust Gas Recirculation (EGR) to meet EPA 2004-2007 emissions standards. ACERT engines are more emissions-compliant but more complex to service.

What maintenance is required for the Cat C15 engine?

Regular maintenance of the Cat C15 engine includes oil and filter changes (typically every 25,000 to 50,000 miles depending on duty cycle), inspection of cooling systems, fuel filter changes, ACERT-specific EGR cooler service (on applicable variants), and monitoring engine diagnostics through the ECM via Cat ET diagnostic software. Proper maintenance helps ensure longevity, with C15 engines routinely reaching 1,000,000+ miles before requiring major overhaul.

Is the Cat C15 engine known for reliability?

Yes, the Cat C15 engine is renowned for its reliability and durability when properly maintained. It is built to withstand tough Class 8 trucking operating conditions and is supported by Caterpillar’s extensive service network and parts availability across North America. The pre-ACERT 6NZ is particularly well-regarded for its mechanical robustness.

How does the Cat C15 engine compare to other engines in its class?

The Cat C15 competes directly with the Cummins ISX, Detroit Diesel 60 Series 14L (and successor DD15), and Volvo D13 / D16. The C15 is known for its robust construction, high torque output, and Caterpillar’s long heritage in heavy-duty diesel design. Among owner-operators, the pre-ACERT C15 6NZ is widely considered one of the most desirable Class 8 truck engines ever produced.

Can the C15 be tuned for higher horsepower?

Yes, particularly the pre-ACERT 6NZ variant. The 6NZ has been tuned to 800+ hp by aftermarket performance shops with appropriate supporting modifications (turbocharger upgrades, fuel system modifications, ECM tuning). ACERT C15 variants are more difficult to tune due to integrated emissions hardware and more conservative factory ECM mapping.