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 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.
| 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. |
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.
Not sure if this fits? Call (240) 301-0095 with your truck VIN or equipment serial number, current engine serial prefix, transmission, and intended application. CAT 3406E configurations vary widely between truck, marine, industrial, and gen-set spec. Our heavy diesel team confirms compatibility before your order ships.
Every used 3406E we ship goes through this process:
This is heavy industrial diesel. Full inspection documentation, including pictures of bottom-end where access permits, is available on request before order confirmation.
| Engine Family | Caterpillar 3406 Inline Six Diesel |
|---|---|
| Generation | 3406E (Electronic | 1993 to 1999) |
| Serial Prefix | 2WS |
| Configuration | OHV | Inline-6 | 24 valves |
| Displacement | 14.6L (893 cu in) |
| Bore X Stroke | 5.40 in x 6.50 in |
| Compression Ratio | 16.5:1 |
| Aspiration | Turbocharged | ATAAC |
| 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 | Approximately 2 | 900 lbs dry |
| Condition | Used OEM | tested and inspected |
Every used 3406E CAT Engine For Sale sold by Vaz Auto Solutions is covered by a 15 day replacement warranty from the date of delivery.
To make a claim, contact us within 15 days of delivery at (240) 301-0095 or info@vazautosolutions.com.
