Mercedes Sprinter / ML / C270 2.7cdi 612 engine
R42,000.00
The Mercedes-Benz OM612 is a 2.7-litre, 5-cylinder inline diesel engine featuring common-rail direct injection (CDI) and a variable-geometry turbocharger. Produced between 1999 and 2007, it is recognized for its high torque and longevity, often powering vehicles like the Sprinter, ML270, and C270 CDI in South Africa.
Core Technical Specifications
| Feature | Specification |
|---|---|
| Type | 5-Cylinder Inline, 20-Valve, DOHC |
| Displacement | 2,685 cc (2.7L) |
| Bore x Stroke | 88.0 mm x 88.3 mm |
| Compression Ratio | 18.0:1 |
| Fuel System | Bosch Common-Rail (CDI) with High-Pressure Pump |
| Timing System | Double roller timing chain |
Performance by Application
The OM612 was tuned differently depending on whether it was used for commercial or passenger applications:
- Sprinter (W901-W904): Detuned for durability, producing 115 kW (156 hp) and 330 Nm of torque.
- C270 CDI (W203) & ML270 CDI (W163): Higher output producing 125 kW (170 hp) and 370–400 Nm of torque.
- C 30 CDI AMG: A high-performance 3.0L variant producing 170 kW (231 hp) and 540 Nm.
Key Design Features
- Inline-5 Layout: A balanced configuration that provides smoother operation than 4-cylinder engines while remaining more compact than an inline-6.
- Aluminum Cylinder Head: Mounted on a cast-iron block for a blend of weight reduction and structural strength.
- Low-Pressure Fuel Pump: Unlike the later OM647, the OM612 uses a mechanical fuel feed pump located on the front of the cylinder head.
- Plastic Fuel Lines: A signature identifier of the OM612 is its transparent plastic fuel lines, which are prone to air leaks over time.
Common Issues & Maintenance
- “Black Death” (Injector Leaks): Carbon buildup around the injectors caused by failing copper crush seals. If ignored, the injectors can become permanently stuck in the head.
- Swirl Flap Failure: The plastic flaps in the intake manifold can wear out, causing boost leaks or rough idling.
- Fuel Rail Pressure Regulator: Failure of this component is a common cause of “hunting” or unstable idling.
- Coolant & Oil Leaks: The oil cooler is a known failure point where oil and water can mix.