Mercedes Benz
OM 654
Manufacturer:	Mercedes Benz
Production period:	since 2016
How it works:	diesel
Style:	In-line engine , four-cylinder
Engines:	1.6 liters (1598 cm³) 2.0 liters (1950 cc)
Previous model:	OM 651 , OM 626
Successor:	none
Similar models:	OM 656

The OM 654 is a diesel engine from Mercedes-Benz , which was introduced 2016th The main components are manufactured at the engine plant Stuttgart-Untertürkheim . The engine is assembled at MDC Power GmbH in Kölleda. 

The four-cylinder in - line engine OM 654 is the successor to the OM 651 and part of a new, modularengine generation that will include four- and six-cylinder diesel engines as well as four-cylinder and six-cylinder gasoline engines . Due to the same cylinder stroke (approx. 500 cm³) and distance, a high number of identical parts is achieved. 

The OM 654 is the first all-aluminum diesel four-cylinder engine from Mercedes-Benz. 

The first use of the engine was in the E-Class ( 213 series ), which has been delivered since April 2016. Since 2018, a second variant with a reduced to 1.6 liters displacement is offered. 

Technology 

1.6 liter inline four-cylinder (OM 654 DE 16)

The displacement of the four-cylinder in - line engine is 1598 cc with a bore of 78 mm and a stroke of 83.6 mm, with a cylinder spacing of 90 mm. The crankcase of the engine is made of aluminum, the cylinder head of a high-strength aluminum alloy. There are steel pistons and a so-called CONICSHAPE®  are used.  In contrast to the 2.0-liter version of the engine has no Lanchester balancer shafts .

2.0 liter in-line four-cylinder (OM 654 DE 20) 

The displacement of the four-cylinder in - line engine is 1950 cc with a bore of 82 mm and a stroke of 92.3 mm, with a cylinder spacing of 90 mm. The compression is 15.5. The crankcase of the engine is made of aluminum, the cylinder head of a high-strength aluminum alloy. Steel pistons and a so-called NANOSLIDE® cylinder coating are used. It is an iron-carbon layer by arc wire spraying is applied directly to the aluminum surface and high oil retention volume in the cylinder running surface allows. The engine has two side-mountedLanchester balance shafts .

The change of charge is controlled by four valves per cylinder ( four-valve technology ) and two overhead camshafts driven by a timing chain . The drive sits as in the OM 651 at the rear end of the engine (output side) to keep the height at the front end as small as possible. This allows for a longitudinally installed engine a flat and rearward rising hood in favor of aerodynamics and pedestrian protection.

In the 143 kW variant, the engine weighs 168.4 kg according to DIN standards, which is 35.4 kg less than its predecessor with 125 kW. Runnable and with all ancillaries, the weight saving is even around 46 kg. 

The engine has a water cooled turbocharger from Honeywell (GTD1449) with variable turbine geometry . An electric motor adjusts the vanes. The compressed fresh air is cooled in a charge air cooler .

Furthermore, the engine has both a cooled low-pressure exhaust gas recirculation (EGR) and a cooled high-pressure exhaust gas recirculation. The exhaust of the low-pressure EGR is taken behind the particulate filter, cooled and re-introduced before the compressor.

The entire exhaust aftertreatment takes place close to the engine and has already been designed for future test procedures such as the WLTP cycle and Real Driving Emissions (RDE) . By arranging all elements of the exhaust aftertreatment directly on the engine, the number of engine variants could be reduced compared to the predecessor. Behind the turbine of the turbocharger first a Dieseloxidationskatalysator (DOC) is used, afterwards with a falling-stream mixer the urea solution AdBluenecessary for the purification of the nitrogen oxides is metered. After a short mixing section, an SCR-coated diesel particulate filter (sDPF) and an SCR catalytic converter follow each other .

Injection and combustion 

The common rail injection works with a fuel pressure up to 2050 bar.  The high-pressure pump used is a CP4 stamping pump from Bosch . The pump is driven by the timing chain.

For the first time in a car diesel engine, a step-well combustion process is used. This should lead to a better efficiency compared to an omega trough and at the same time lower particle raw emissions.

Versions 

The OM 654 is available in five power levels (90, 110, 118, 143 and 180 kW).

OM 654 DE 16 G SCR 

OM 654 DE 20 G SCR