Only the second generation of the A-class and the comparable B-class compact van were equipped with the Mercedes OM640 or A-Class 2.0 CDI engine, which was manufactured between 2004 and 2012. With a 1.7-liter capacity, this power unit effectively took the place of the well-liked OM668 diesel engine.
OM616, OM601, OM604, OM611, OM640, OM646, OM651, OM654, and OM668 are members of the diesel R4-family.
The 2.0-liter in-line, four-cylinder OM640 diesel engine comes with a turbocharger and Common Rail direct injection in a range of power ratings.
The cylinder block could not be made of aluminum due to the engine compartment’s limited space, increased displacement, and high ignition pressure needed as a result of the increased power. As a result, the OM640 engine’s cylinder block is composed of cast iron rather than having individual cast iron liners. Although there is an 18 kg weight increase as a result, the engine noise level is decreased. Each cylinder has two camshafts and four valves, and the cylinder head is composed of high-strength aluminum. Roller tappets with hydraulic compensators operate the valves.
It’s interesting to note that the Thielert Centurion 2.0 aircraft engine is based on the OM640. Additionally, the Austro Engine AE-300/330 aircraft engine in the Diamond DA-42 and DA-62 aircraft uses it as a base.
Specifications
| Production years | 2004-2012 |
| Displacement, cc | 1991 |
| Fuel system | Common Rail |
| Power output, hp | 82 (DE 20 LA red 160 CDI) 109 (DE 20 LA red 180 CDI) 136 – 140 (DE 20 LA 200 CDI) |
| Torque output, Nm | 180 (DE 20 LA red 160 CDI) 250 (DE 20 LA red 180 CDI) 300 (DE 20 LA 200 CDI) |
| Cylinder block | cast iron R4 |
| Block head | aluminum 16v |
| Cylinder bore, mm | 83 |
| Piston stroke, mm | 92 |
| Compression ratio | 18.0 |
| Features | EGR |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | IHI VV16 (DE 20 LA red 160 CDI) IHI VV16 (DE 20 LA red 180 CDI) BorgWarner BV43 (DE 20 LA 200 CDI) |
| Recommended engine oil | 5W-30 |
| Engine oil capacity, liter | 5.8 |
| Fuel type | diesel |
| Euro standards | EURO 3/4 |
| Fuel consumption, L/100 km (for Mercedes A160 CDI 2008) — city — highway — combined |
5.4 3.9 4.5 |
| Engine lifespan, km | ~280 000 |
| Weight, kg | 160 |
The engine was installed on:
- Mercedes A-Class W169 in 2004 – 2012;
- Mercedes B-Class W245 in 2005 – 2011.
Disadvantages of the OM640 engine
With electromagnetic injectors and Bosch Common Rail, this diesel engine is incredibly dependable.
Contamination of the metering flap or EGR valve is the primary cause of the issues.
Check the fuel pressure control valve in the rail if you are having trouble starting.
A generator, a thermostat, and a boost pressure sensor are examples of low resources.
It should be remembered that lowering the motor and subframe together is often required.