3. Quick Answer Block

What is a used Cummins engine? It’s a factory-original (OEM) Cummins diesel engine removed from a Dodge or Ram truck (or, for the smaller 4BT/6BT industrial variants, from an industrial or off-road application) that was totaled, retired, or parted out. It has not been rebuilt or remanufactured; it’s the original assembly, usually tested or inspected before resale.

How much does a used Cummins engine cost? Most used Cummins engines range from $2,000 to $7,500 depending on the generation, compared to $9,000 to $15,000+ for a new or remanufactured 6.7L replacement plus labor.

Why buy used OEM instead of remanufactured or new? A used OEM Cummins comes from the same assembly line as the one currently in your truck, with no aftermarket internal components. It’s often the fastest and most cost-effective way to source a proven diesel, especially since Cummins engines are known for high mileage potential when properly maintained, so a used unit from a well-cared-for donor truck can still have significant service life left.

How does Used Auto Parts Pro help? We match your Ram or Dodge truck’s VIN to compatible listings across our verified seller network, so you get strong fitment confidence before you buy, then you compare quotes (shipping included) from multiple sellers instead of negotiating with one salvage yard.

4. Key Takeaways

• Cummins has powered Dodge and Ram trucks across at least five distinct generations since 1989, from the mechanical 12-valve through the VP44-injected and common rail 24-valve engines to the current 6.7L, plus smaller 4BT/6BT industrial variants popular in off-road and swap applications.
• Used pricing typically runs $2,000 to $7,500 depending on generation, with the current 6.7L and swap-popular 4BT/6BT toward the higher end due to demand.
• VIN matching gives strong fitment confidence, not an absolute guarantee. Always confirm the physical engine code and generation against the listing before installation.
• Warranty terms vary by seller and by part. UAPP does not set a universal warranty; sellers in our network set their own terms, and many offer coverage you should confirm in writing.
• Inspection and testing practices vary by seller and by engine. Ask each seller directly what testing was performed before you buy.
• Shipping cost is included in the seller’s quoted price for the contiguous 48 states; it is not billed as a separate “free shipping” promotion.
• Cummins Inc. reached a record $1.675 billion civil penalty settlement with the Department of Justice and the state of California over emissions test cheating and defeat devices found on certain 2013-2019 Ram 2500/3500 trucks with 6.7L (and some 5.0L) Cummins engines, and separate consumer class action litigation against FCA/Ram and Cummins covers a similar range of model years. If your truck falls in this range, check directly with Ram/Stellantis and Cummins for details on any applicable remedy before sourcing an independent replacement.
• Emissions system components (DPF, EGR, DEF/SCR system) on 2007.5-and-later Cummins engines are regulated equipment; removing or bypassing them is illegal for on-road use and can affect resale value and compliance.
• Used Auto Parts Pro is a marketplace that connects buyers to a nationwide network of sellers. We do not hold inventory and we do not sell engines directly.

5. Product Overview

Cummins has supplied the diesel engine option in Dodge and Ram heavy-duty pickups since 1989, and the partnership has become one of the most recognized engine-and-truck pairings in the industry. Unlike most gas engine turnover cycles, Cummins diesels are built for high-mileage durability, with well-maintained examples commonly exceeding 300,000 to 500,000 miles before needing major internal work.

Engines fail for a mix of predictable reasons: injection pump or injector failure from contaminated fuel or age, head gasket failure under high boost on modified trucks, cracked pistons from excessive fueling modifications, EGR and DPF system neglect leading to secondary engine damage on newer emissions-equipped units, or, in some cases, a known manufacturing or design issue tied to a specific generation. Owners typically start shopping for a replacement after a shop diagnoses internal damage that isn’t cost-effective to repair, or after an engine is damaged in an accident that otherwise leaves the truck drivable.

6. Engine Generations (by Injection System and Model Year)

Cummins diesel engines used in Dodge and Ram trucks fall into several distinct generations, primarily distinguished by their fuel injection system. Confirm your exact engine generation and injection system (usually identifiable by model year and a visual check of the injection pump or fuel rail) before buying; a “5.9 Cummins” from one generation is not necessarily interchangeable with a “5.9 Cummins” from another.

5.9L 12-Valve (Mechanical, P7100 Injection Pump)

Applications: 1989-1998 Dodge Ram 2500/3500, using a fully mechanical Bosch P7100 injection pump with no electronic engine controls.

Typical used price range: $2,500 to $4,500, with strong demand from both truck owners and off-road/swap builders due to its mechanical simplicity.

Known issue to watch for: The “killer dowel pin” (KDP), a small dowel pin that can work loose and cause serious internal damage if not addressed proactively; ask the seller whether this has been checked or corrected on the donor engine.

5.9L 24-Valve, VP44 Injection Pump

Applications: 1998.5-2002 Dodge Ram 2500/3500, introducing electronic injection control via the Bosch VP44 rotary pump.

Typical used price range: $2,000 to $3,800.

Known issue to watch for: VP44 pump failure, particularly on trucks that were chip-tuned or run hard, since the VP44 was more failure-prone under increased fueling than the mechanical pump it replaced. Ask about tuning history on the donor truck.

5.9L 24-Valve, Common Rail (CP3 Injection Pump)

Applications: 2003-2007 Dodge Ram 2500/3500, moving to a common rail fuel system with a Bosch CP3 injection pump.

Typical used price range: $2,500 to $4,200.

Known issue to watch for: Generally more reliable than the VP44 generation, though early 2003 production is sometimes associated with block casting quality concerns; ask the seller about the exact production date if buying from this range.

6.7L Cummins (2007.5-2018)

Applications: 2007.5-2018 Dodge/Ram 2500/3500/4500/5500, Cummins’ first 6.7L displacement, introducing emissions equipment (DPF, and later SCR/DEF systems).

Typical used price range: $3,500 to $6,000.

Known issue to watch for: EGR cooler failure and DPF clogging on trucks with neglected maintenance or frequent short-trip driving; ask about emissions system service history and any fault code history from the donor truck.

6.7L Cummins (2019-Present, High-Output Variants)

Applications: 2019-present Ram 2500/3500/4500/5500, including newer high-output configurations.

Typical used price range: $4,500 to $7,500.

Known issue to watch for: This generation falls within the range covered by Cummins’ emissions settlement described in the Common Problems section below. Complex electronic controls also mean a used unit should be sourced with matching ECM data whenever possible.

4BT / 6BT (Industrial and Off-Road Swap Variants)

Applications: Not originally installed in Dodge or Ram pickups; these smaller-displacement industrial Cummins engines (3.9L four-cylinder and 5.9L six-cylinder) are popular swap engines for Jeeps, off-road builds, and light equipment, sourced from industrial, agricultural, or marine applications.

Typical used price range: $3,000 to $6,000, reflecting strong demand from the swap community relative to available industrial supply.

Known issue to watch for: Confirm the exact application and accessory configuration, since industrial 4BT/6BT engines vary significantly in accessory mounting, rotation, and emissions equipment depending on their original equipment use.