ENGINE MERCEDES 642920 OM642.920 3.0 CDI V6 320 91TKM COMPLETE

Mercedes-Benz OM642.920 engine with 91,000 km (91tkm) is considered a “mid-life” acquisition. This 3.0L V6 Turbo Diesel is widely respected for its torque and longevity, but at this specific mileage and age, there are critical maintenance items that determine whether the engine is a bargain or a project.

1. Technical Identification

• Engine Code: OM642.920 (Part of the OM642 engine family).

• Configuration: 3.0L V6 24V Turbo Diesel.

• Power Output: ~165 kW / 224 hp.

• Torque: 510–540 Nm.

• Primary Applications: * Mercedes-Benz E320 CDI (W211) (Facelift)

  • Mercedes-Benz CLS320 CDI (W219)

• Fuel System: Bosch Common Rail with Piezo injectors.

2. 2026 Market Valuation (Estimated USD/EUR)

A “complete” engine at 91tkm (including the turbocharger, fuel injectors, and high-pressure pump) is a valuable unit for owners of classic W211/W219 diesels.

3. Critical “While It’s Out” Maintenance

The OM642 has a few “Achilles’ heels.” Since the engine is currently out of the car, you can save thousands in future labor by addressing these now:

• Oil Cooler Seals (The “Purple” Seals): The original seals in the “V” of the engine fail and cause a massive oil leak that drips down the back of the block. If this engine still has the old orange seals, replace them now with the updated Viton (purple) seals.

• Swirl Flap Actuator (EKAS): Oil often drips from the turbo inlet onto the swirl flap motor, shorting it out. Check the motor and ensure the intake manifolds aren’t excessively clogged with carbon/soot.

• Turbo Inlet Seal: Always install a brand-new “red” turbo inlet seal. A loose seal here is the primary cause of the aforementioned swirl flap motor failure.

• PCV Valve: At 91tkm, the PCV valve is likely tired. Replacing it prevents oil vapor from fouling the turbo and intake system.

4. Installation & Compatibility

• Injector Coding: The OM642 uses Piezo injectors. Each injector has a specific calibration code (IMA code). You must use a Xentry/Star Diagnosis tool to code these into your car’s ECU, or the engine will have a rough idle and poor fuel economy.

• Drivetrain: The .920 is specifically for Rear-Wheel Drive (RWD) applications. If you are trying to swap this into a 4MATIC vehicle, the oil pan and oil pickup will need to be swapped from your old engine.

• Oil Specification: Only use MB 229.51 or 229.52 spec oil. Using non-low-ash oil will clog the Diesel Particulate Filter (DPF) within a few thousand miles.

5. 2026 Buying Tip