What are the main advantages of the OM642 engine?

Massive torque of up to 620 Nm from a 3.0L displacement gives effortless pulling power for large vehicles and towing Smooth and surprisingly quiet for a diesel engine - the V6 layout provides inherent balance that four-cylinders cannot match Strong mid-range delivery makes overtaking and highway cruising genuinely effortless across the vehicle range Wide power range (204–258 hp) allows one engine family to serve everything from Vito vans to ML-Class luxury SUVs Chain drive eliminates belt replacement costs - with correct maintenance, the drivetrain is inherently durable

What are common issues and problems with the OM642?

The EGR cooler and swirl flap system are notorious weak points - broken swirl flaps can cause catastrophic engine damage if not addressed Intake manifold swirl flap actuator failures are extremely common - many owners remove the flaps preventively as a precaution Turbocharger failures can be expensive, especially on high-mileage examples or those poorly maintained Injector issues develop after 150,000–200,000 km, causing rough running, hard starting, and increased smoke This is a complex, expensive engine to service - always use correct Mercedes-spec oil and don't skip service intervals

What torque does the OM642 engine produce?

The OM642 engine produces 500-620 Nm.

What is the compression ratio of the OM642 engine?

The compression ratio of the OM642 engine is 15.5:1.

How much displacement does the OM642 engine have?

The OM642 engine has 3.0L (2987 cc) of displacement.

What is the fuel consumption of the OM642 engine?

Reported fuel consumption for the OM642 engine is 6-8 L/100km.

Mercedes-Benz OM642 Engine Specs

Mercedes-Benz

Quick overview

Mercedes-Benz OM642 is a 3.0L (2987 cc) diesel engine with 204-258 HP, 500-620 Nm, 15.5:1 compression ratio. Fuel consumption: 6-8 L/100km. Typical service life: 400,000+ km with proper maintenance.

204-258

3.0L (2987 cm³)

Displacement

500-620 Nm

Torque

Diesel

Fuel

Description

The OM642 is Mercedes-Benz's 3.0-liter V6 diesel engine, produced from 2005 to 2018. This engine represents Mercedes' approach to modern diesel technology, offering a good balance of performance, refinement, and efficiency.

General Information

Production Years: 2005-2018

Fuel Type: Diesel

Environmental Standards: Euro 4/5/6

Fuel Consumption: 6-8 L/100km (29.4-39.2 mpg)

Power (HP): 204-258

Power (kW): 150-190

Displacement: 3.0L (2987 cm³) (182.3 cu.in)

Torque: 500-620 Nm (369-457 lb-ft)

Cylinder Block Alloy: Aluminum alloy

Cylinder Head Alloy: Aluminum alloy

Has Turbo: Yes

Engine Layout: V6

Aspiration Type: Turbocharged

Fuel System: Common Rail Direct Injection

Head Type: DOHC, 24 valves

Timing Drive: Timing Chain

Cooling Type: Liquid Cooled

Engine Cycle: Diesel Cycle

Cylinders Count: 6

Technical Details

Total Valves: 24

Firing Order: 1-4-2-5-3-6

Compression Ratio: 15.5:1

Hydraulic Lifters: No

Maintenance

Oil Capacity: 8.5L (9 qts)

Recommended Oil: Mercedes-Benz MB 229.51 5W-30 Diesel

Operating Temperature: 80-105°C (176-221°F)

Service Life (km): 400,000+ km with proper maintenance (249 miles)

Timing Belt/Chain Interval: Chain - no replacement needed

Scores

Reliability

Economy

Power

Values 1–100. Calculated from engine specs.

Advantages

+ Massive torque of up to 620 Nm from a 3.0L displacement gives effortless pulling power for large vehicles and towing
+ Smooth and surprisingly quiet for a diesel engine - the V6 layout provides inherent balance that four-cylinders cannot match
+ Strong mid-range delivery makes overtaking and highway cruising genuinely effortless across the vehicle range
+ Wide power range (204–258 hp) allows one engine family to serve everything from Vito vans to ML-Class luxury SUVs
+ Chain drive eliminates belt replacement costs - with correct maintenance, the drivetrain is inherently durable

Pay Attention

! The EGR cooler and swirl flap system are notorious weak points - broken swirl flaps can cause catastrophic engine damage if not addressed
! Intake manifold swirl flap actuator failures are extremely common - many owners remove the flaps preventively as a precaution
! Turbocharger failures can be expensive, especially on high-mileage examples or those poorly maintained
! Injector issues develop after 150,000–200,000 km, causing rough running, hard starting, and increased smoke
! This is a complex, expensive engine to service - always use correct Mercedes-spec oil and don't skip service intervals

Used in Vehicles

Mercedes-Benz C-Class (1993-2023)

E-Class (1953-2023)

ML-Class (1997-2015)

GL-Class (2006-2016)

Sprinter