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Description
About the Mercedes 300D Engine
This is the OM617.952, the 3.0L inline-five turbo-diesel that powers the classic Mercedes 300D Turbodiesel, as the live page describes. It is mounted longitudinally and uses a Garrett T3 turbocharger for responsive low-end power, Bosch mechanical indirect injection with a precombustion chamber for smooth, efficient combustion, and a cast-iron block with reinforced internals for the durability the OM617 is famous for. A mechanical fuel pump runs the show, which is part of why this engine is so repairable and long-lived. It makes about 123 hp and 184 lb-ft, and it formed the foundation of Mercedes’ diesel reputation in the United States and Europe in the 1980s.
Why 300D Owners Replace the Engine
Very high mileage and the natural wear of a 40-year-old engine are the usual reasons, though many of these engines are replaced simply to refresh a cherished classic. A sound OM617 restores the unmistakable W123 driving feel, the steady turbo-diesel torque, and the legendary durability, with the engine inspected for compression before it ships. Because it is a classic mechanical diesel, the swap is refreshingly simple: no ECU to flash, no emissions modules to integrate.
Things to Confirm Before Ordering
- Your exact W123 year and chassis, confirmed by VIN; the listing tags a 1981 donor, so the year and chassis should be reconciled to your vehicle
- Your fuel and oil plan: this engine uses diesel fuel, glow plugs, and high-quality diesel-rated oil, not gasoline-engine service
- Your local rules: this is a pre-modern-emissions classic diesel, so confirm any state or local requirements for a vehicle of this era
What Is Included, What Is Not Included
| Detail | Description |
|---|---|
| INCLUDED | The OM617.952 3.0L inline-5 turbo-diesel engine assembly as photographed; confirm the exact configuration at order. |
| NOT INCLUDED | Transmission, accessories not pictured, and fluids; transfer your undamaged accessories at install. |
| Tools You Need | Standard engine-swap tools, diesel-rated oil and a new filter, clean diesel fuel, and basic mechanical-diesel know-how; there is no ECU to program. |
Vehicle Compatibility
| Detail | Description |
|---|---|
| Mercedes 300D, OM617.952 3.0L inline-5 turbo-diesel (donor tagged 1981) | VIN confirmed at order |
| Chassis note | The OM617 turbo-diesel powered the W123 300D and related models; confirm exact year and chassis by VIN |
| Diesel note | Classic mechanical diesel: diesel fuel, glow plugs, diesel-rated oil, no modern aftertreatment |
| Reference Application | 1981 Mercedes 300D Engine (W123, year to be confirmed) |
Fitment Assistance
Call (240) 301-0095 with your VIN. Because the OM617 appeared across several W123 models and years, we confirm your exact chassis and model year before the engine ships, and we are glad to talk through this simple, durable mechanical diesel.
Condition and Inspection
This is a used diesel engine, inspected before shipping:
- Compression checked across all five cylinders
- Garrett T3 turbocharger inspected for play and leaks
- External surfaces checked for oil and fuel leaks
- Mechanical injection pump inspected for condition
- Photos provided before purchase
Why Buy from Us
- Accuracy: described as the classic mechanical diesel it is, with no false modern-emissions claims
- Correct engine: the OM617 3.0 turbo-diesel the 300D actually uses
- Compression and turbo inspected before sale
- Free shipping to all 50 states, no hidden fees
- No core charge, keep your old engine
- 15 day replacement warranty
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