3406E CAT Engine for Sale | OEM Caterpillar 14.6L Inline-6 Diesel (2WS Prefix)
$18,000.00
Product Overview
- Displacement: 14.6L (893 cu in)
- Engine Family: Caterpillar 3406 Inline-Six Diesel
- Configuration: Inline-6, OHV, 24 valves
- Horsepower: 355 to 550 hp by calibration
- Condition: OEM used, tested and inspected
- Availability: 2WS prefix available, other prefixes on request
- Shipping: Free crated heavy freight to all 50 states, 7 to 14 business days
- All 6 cylinders compression tested with results shared before payment
- Engine hours documented where available
- Serial number and prefix confirmed before shipping
- Top end and bottom end inspection documented
- 100% application fit verified before every order ships
- Zero core charge required, your existing engine stays with you
- Backed by a 15 day replacement warranty against internal defects
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Description
Engine Background
The Caterpillar 3406E is the electronically controlled evolution of the legendary CAT 3406 inline-six diesel that powered Class 8 over-the-road trucks, heavy industrial equipment, marine pleasure craft, and standby generators for decades. Produced from 1993 to 1999 in this exact configuration, the 3406E was Caterpillar’s answer to growing emissions regulations and demand for electronic engine management while preserving the bulletproof inline-six architecture that made the 3406 family famous.
The 3406E delivers 355 to 550 horsepower and 1,350 to 1,850 lb-ft of torque from 14.6 liters of displacement, depending on the specific calibration and application. Internally it uses a cast iron block, single-piece cast iron head, four valves per cylinder, electronically controlled HEUI injectors, and turbocharged air-to-air aftercooled charge air. The combination of cast iron mass, conservative bore/stroke geometry, and electronic engine control gives the 3406E its trademark reputation: million-mile service life with proper maintenance.
The 2WS Prefix
The 2WS prefix on a 3406E serial number identifies engines built at a specific Caterpillar plant during a specific production window. Many fleet operators and rebuilders specifically seek 2WS prefix units because the parts compatibility, calibration history, and known service characteristics are well documented in the CAT service network. Tell us your truck VIN, equipment serial number, or current engine prefix and we confirm 2WS compatibility before order.
Common 3406E Applications
- Class 8 trucks: Peterbilt 379, Kenworth W900, Freightliner FLD120, International 9900
- Heavy haul: dump trucks, log trucks, water tanker trucks
- Industrial: rock crushers, asphalt plants, large compressors
- Marine: pleasure cruisers, commercial fishing, workboats
- Generator sets: standby and prime power applications
- Off-road equipment: large wheel loaders, articulated dumpers
When Replacement Becomes Necessary
- Excessive blow-by past breather, ring or liner wear
- Coolant in oil, head gasket or liner seal failure (rebuild candidate)
- Crank or main bearing knock under load
- Loss of power across all speeds, turbo or fuel system wear
- High oil consumption beyond one quart per 8 hours of operation
- Persistent coolant leaks from O-rings on liner pack
What Ships and What Does Not
| INCLUDED | Complete engine: block, crankshaft, rods, pistons, camshaft, head, valve train, oil pan, valve cover, turbocharger, fuel system components present on donor unit, water pump, oil pump. |
|---|---|
| NOT INCLUDED | ECM (sometimes available separately, call to discuss), engine harness, exhaust manifolds (sometimes included), starter, alternator, accessory drive, clutch and flywheel, motor mounts, front cover assembly. |
| Fluids | Drained before shipping. Refill with CAT-spec 15W-40 diesel motor oil. Always pre-lube before first crank. |
| Core Note | No core charge. You are not required to return your old engine. |
Direct-Fit Vehicle and Equipment Applications
The 3406E was a direct fit in the following:
| Peterbilt 379, 378, 357 | 1993 to 1999 (3406E spec'd) |
|---|---|
| Kenworth W900, T800, T600 | 1993 to 1999 (3406E spec'd) |
| Freightliner FLD120, Classic XL | 1993 to 1999 (3406E spec'd) |
| International 9900, 9800, 9300 | 1993 to 1999 (3406E spec'd) |
| Mack RD-Series | Some 1993 to 1999 spec configurations |
| Industrial Equipment | CAT 988, 992 wheel loaders (industrial trim), CAT 5230 excavator (genset trim), various crushers and compressors |
| Marine | Pleasure craft, commercial fishing boats, workboats spec'd for 3406E |
| Generator Sets | CAT 3406E gen-set models 350 kW to 600 kW range |
Application is everything for an industrial diesel of this size. Tell us your truck make, model, transmission, gear ratio, and intended use. We confirm bell-housing pattern, accessory drive, mounting points, and ECM compatibility before every order ships.
Inspection Workflow
Every used 3406E we ship goes through this process:
- Compression test across all 6 cylinders with pressure per cylinder recorded
- Visual inspection of block, head, and liner pack
- HEUI injector and HEUI pump operation inspected
- Turbocharger shaft play, wastegate, and aftercooler inspected
- Crank and rod bearing inspection where access permits
- Engine hours recorded where ECM data is available
- Serial number, prefix, and CAT-spec calibration documented
- Donor application, hours, and operating history disclosed where available
This is heavy industrial diesel. Full inspection documentation, including pictures of bottom-end where access permits, is available on request before order confirmation.
Why Buy From Part Nests
- All 6 cylinders compression-tested with results shared before payment
- Engine hours documented where ECM data is available
- Serial prefix (2WS or other) confirmed for your spec
- Application fit verified for truck, marine, industrial, or gen-set use
- Free heavy crated freight to all 50 states with care for the engine value
- No core charge required
- 15 day replacement warranty on internal defects
- Call (240) 306-7051 to speak with someone who knows 3406E serial prefix identification, truck versus marine versus gen-set calibration, and HEUI fuel system service planning
Additional information
| engine-family | Caterpillar 3406 Inline Six Diesel |
|---|---|
| generation | 1993 to 1999), 3406E (Electronic |
| serial-prefix | 2WS |
| configuration | 24 valves, Inline 6, OHV |
| displacement | 14.6L (893 cu in) |
| bore-x-stroke | 5.40 in x 6.50 in |
| compression-ratio | 16.5:1 |
| aspiration | ATAAC, Turbocharged |
| fuel-system | HEUI Electronically Controlled Unit Injectors |
| fuel-type | Diesel |
| block-material | Cast Iron |
| head-material | Cast iron, single-piece |
| cooling-system | Liquid cooled with thermo fan clutch |
| electrical-system | 12V or 24V by application |
| production-years | 1993 to 1999 |
| horsepower | 355 to 550 hp by calibration |
| torque | 1, 350 to 1, 850 lb-ft by calibration |
| engine-weight | 900 lbs dry, Approximately 2 |
| condition | tested and inspected, Used OEM |
The 2WS prefix on a 3406E serial number identifies engines built at a specific Caterpillar plant during a specific production window. Many fleet operators and rebuilders specifically seek 2WS prefix units because parts compatibility, calibration history, and known service characteristics are well documented in the CAT service network. Tell us your truck VIN, equipment serial number, or current engine prefix when ordering.
Electronic engine management. The 3406B and 3406C used mechanical injection pumps. The 3406E (1993 to 1999) introduced HEUI (Hydraulically actuated Electronic Unit Injectors) controlled by an ECM. The 3406E was Caterpillar's answer to emerging emissions regulations while preserving the inline-six architecture. Output range and basic durability are similar; the 3406E is more tunable through ECM calibration.
Million-mile service lives are common with proper maintenance. Fleet operators routinely document 1.2 to 1.5 million miles before major overhaul. The cast iron block, single-piece cast iron head, conservative bore/stroke geometry, and high-volume oil cooling are the foundation of this longevity. Even higher mileage is possible with disciplined oil change intervals and coolant maintenance.
Hydraulically actuated Electronic Unit Injectors. HEUI uses high-pressure engine oil (separate from lubrication oil pressure) to actuate the injectors, with electronic timing control from the ECM. The system delivers higher injection pressures than mechanical pumps and allows pilot injection for smoother combustion. HEUI requires a dedicated high-pressure oil pump and clean oil with the correct CAT specification.
Usually no, but sometimes. The ECM is typically reused from the donor truck and may or may not be available separately. Call to discuss your specific situation. For some 3406E configurations, ECM swap requires CAT dealer reflashing to match the receiving truck's calibration.
Class 8 over-the-road trucks (Peterbilt 379, Kenworth W900, Freightliner FLD120, International 9900), heavy industrial equipment (CAT 988 and 992 wheel loaders, rock crushers, asphalt plants), marine pleasure craft and workboats, and standby and prime power generator sets in the 350 kW to 600 kW range. The 3406E was one of the most widely deployed Class 8 truck diesels of its era.
Yes if your Peterbilt 379 is the 1993 to 1999 model year with a 3406E originally specified. The bell-housing pattern, mounting points, and accessory drive match the original. For other Peterbilt models or different year ranges, accessory drive and mounting may differ. We confirm 100% fitment before every order.
No. There is no core return required.
15 Day Replacement Warranty
Every used Caterpillar 3406E engine purchased through Part Nests carries a 15 day replacement warranty starting on the delivery date.
What Is Covered
- Internal defects already present when the engine arrives
- Performance materially different from how the engine was described
- Incorrect part shipped due to an error on our end
What Is Not Covered
- Damage caused during installation
- Damage from operation without proper pre-lube before first crank
- Damage from non-CAT-specification fluids
- External components unless specifically itemized
- Labor expenses of any kind
To start a warranty claim, reach us within 15 days of delivery at (240) 306-7051.
- Compression Tested: All 6 cylinders with pressure per cylinder recorded
- Engine Hours Documented: Recorded where ECM data is available
- Serial Prefix Verified: 2WS or other prefix confirmed for your spec
- HEUI System Inspected: Injectors and HEUI pump operation evaluated
- Application Fit Verified: Truck, marine, industrial, or gen-set confirmed
- 15 Day Replacement Cover: Internal defects protected from delivery onward
2 reviews for 3406E CAT Engine for Sale | OEM Caterpillar 14.6L Inline-6 Diesel (2WS Prefix)
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Travis B. –
Got a 2WS prefix 3406E for a 1997 Peterbilt 379 replacement. Serial prefix confirmed up front, all six cylinders compression-tested with results shared before I paid, HEUI injector operation inspected. Engine hours documented from ECM data. Heavy crated freight arrived properly secured. Truck is back on the road.
Mark E. –
Sourced a 3406E for an industrial application repower (rock crusher). Application fit confirmed for industrial use, serial prefix verified, top-end and bottom-end inspection documented with photos. Honest pre-purchase discussion about ECM compatibility for the application. Foundation for the repower project is exactly the right engine.