Mercedes New Workhorse – the OM 654
From large sprinter vans to small C-Class sedans, the OM was reliable, durable and fuel efficient. It held its own against its larger brothers, too, like the venerable 3. However, the OM has been discontinued, replaced with the new-generation OM With nearly a decade of development and engineering, expectations were already high, never mind filling the shoes of the OM On paper, this thing looks up to the task.
OM — Technical Changes The most drastic change made to the OM is the literal flip-flopping of engine materials. Traditionally the engine block would be made from cast iron, while the pistons were aluminum.
Aluminum pistons were lighter, resulting in better power and engine response. However, by making pistons out of steel the overall size of the piston could be reduced. Finally, by switching the block to aluminum, the overall engine weight was significantly reduced. OM — Fuel Efficiency The latest trends in engine designs have focused not on power, but on reducing internal inefficiencies like airflow and friction.
Mercedes claims the new OM has a quarter less internal friction versus the OM, and, with improved airflow, results in a net fuel savings of about 13 percent. For a full-size luxury sedan, that is very impressive. OM — Power Power will vary slightly depending on the application, but, the first model that Mercedes used the new OM in is the E d. In that vehicle the OM is rated for HP and lb-ft of torque. Not too shabby for a 2. Oh oh! Vehicle manufacturers always design their vehicle and engine around the limits placed on them by emissions regulations.
Getting certified meant passing an emissions test, therefore the focus was on passing the test — or cheating, in VWs case. This means that the components and tuning have been designed from the ground up to remain emissions complaint in all working conditions, not just in the test environment. Mercedes claims the engine was designed not for current standards but to exceed even future standards USA? If the OM is truly a power plant designed around exceeding distant emissions standards it would seem that bringing it to the US would be a great fit.
Mercedes-Benz common problems
New Mercedes four cylinder engine M and OM M with ISG and 48V system Mercedes electrifies 2 liter diesel and petrol engines with a volt network and integrated starter generator. In Mercedes launched a new family of diesel engines and the first version was a 2-liter four-cylinder OM debuted on the latest generation E-Class in In , Mercedes presented on the facelifted S-Class the diesel version with six cylinders OM with HP and HP and the petrol version with six cylinders M with mild-hybrid system and 48V network with and HP respectively.
ISG and 48V on the new four cylinder diesel and petrol Mercedes engines Now, the two new four-cylinder diesel OM M M from modified and petrol M will be equipped for the first time with a volt electrical system and an integrated starter generator.
This increases the maximum power by 22 HP and the maximum torque by Nm petrol and Nm at diesel Newton meters. New engines will debut in the facelifted MercedesE-Class. Mercedes was the first manufacturer to use the integrated starter generator ISG in on the OM engine. The purpose of this technology, which is also known as the mild hybrid, lies in the increase in comfort and fuel savings.
The small 22 HP electric motor cannot propel the car alone but it supports the combustion engine at accelerations and starting on the spot, ie exactly where the combustion engine consumes the most. Thanks to the volt electrical system used, the ISG can start the combustion engine much faster and more gently than a conventional volt starter offerind more comfort and refinement. At the same time, the ISG is used to generate energy in drive mode and can also support the combustion engine with its torque when the power is high.
The electric motor, power electronics and transmission cooler were installed directly on the transmission in order to reduce the weight of the necessary components no cables and to increase efficiency. These engines are very flexible and can be adapted easily for use in plug-in hybrid environments. M belong to the same family with M and has electrical compressor powered by 48V network The M four-cylinder petrol engine is a completely new development and is belonging from the same engine family with M six-cylinder petrol.
The two-liter machine is the successor of the M and produces up to hp, while the maximum torque is Nm. A special feature of this engine family is the electric compressor powered by the 48V network that is responsible for quickly building up the boost pressure at low engine speed.
An overboost function allows the maximum power to be increased by a further 41 hp for up to 30 seconds when there is a high power requirement. Mercedes claims that OM M engine is the first diesel in the world with an integrated starter generator.
The revised two-liter turbo-diesel four-cylinder has received a new crankshaft and the displacement has increased by 43 cmc to 1, cmc. At the same time, the injection pressure is increased from 2, to 2, bar. The starter generator briefly delivers an additional 22 HP and Nm.
Mercedes OM654 Tuning
Leaving aside the fact that no technology in history has ever turned out to be future proof, this does seem to be an impressive new engine. There are plans for several output variants as well as longitudinal and transverse installation in vehicles with front- rear- and all-wheel drive.
Mercedes DPF Delete
The new engine replaces the current 2. Despite its lower capacity it promises to deliver and increase of power from kW to kW. M belong to the same family with M and has electrical compressor powered by 48V network The M four-cylinder petrol engine is a completely new development and is belonging from the same engine family with M six-cylinder petrol. The two-liter machine is the successor of the M and produces up to hp, while the maximum torque is Nm.
A special feature of this engine family is the electric compressor powered by the 48V network that is responsible for quickly building up the boost pressure at low engine speed. An overboost function allows the maximum power to be increased by a further 41 hp for up to 30 seconds when there is a high power requirement. Mercedes claims that OM M engine is the first diesel in the world with an integrated starter generator.
The revised two-liter turbo-diesel four-cylinder has received a new crankshaft and the displacement has increased by 43 cmc to 1, cmc. At the same time, the injection pressure is increased from 2, to 2, bar. Fuelling Don't miss you'll need to raise the fuel delivery when you are increasing the bhp - it makes the car more thirsty. We strongly recommend you to over specify your flow rate on the injectors.
All-new Mercedes-Benz diesel engine will cut emissions
We think this one is common sense, but you'll need to match your fuel injector to the type of fuel your car uses as well. OM Performance Exhausts You only need to to uprate your exhaust if the existing exhaust is actually causing a restriction. On most factory exhausts you should find that your flow rate is still good even on modest power gains, but when you start pushing up the power levels you will need to get a better flowing exhaust. Sports exhausts can usually air flow out of the engine but avoid an exhaust that is too big or you might just stuff your flow rate and make things worse.
So generally speaking, keep to a size of 1. Common exhaust restrictions are in the filters installed, so adding a better flowing performance catalyst removes the restriction.
Mercedes-Benz Debuts New Four-Cylinder Diesel
We note that performance cats perform similarly to decats and have the added benefit of keeping your car street legal, as decats or catalyst removal is illegal in most territories for road going cars. Few problems should happen as long as they are regularly serviced and maintained. Carbon build up in the head, particularly around the valves which will sap power or create flat spots, this is a larger issue on direct injection engines but should be looked out for on all engines.
We have tips on removing carbon build up. Some of our members have had issues with flat spots or glitches after applying mods and upgrades or tuning, this is not usually related to this engines design, so instead see our article on diagnosing flat spots and problems after tuning which should help you get the bottom of this issue.
Regular oil changes are vital on the OM, especially when tuned and will help extend the life and reliability of the engine.