Mercedes M113: Everything You Need To Know

For many years, AMG took pride in making incredible engines and tuned them to be almost perfect. They mastered their craft and even earning the title as the first automakers to install superchargers on a mass-produced vehicle back in 1921 – talk about longevity. These cars have a nod from Mercedes themselves bearing the “Kompressor” nameplate since that day.

With that, the mighty Kompressor engine was one of their best creations. This supercharged V8, known as M113K, rallied and was considered one of Mercedes’ best to ever come out from their plant.

But there’s more to the M113K, how it evolved and how Mercedes achieved it.

Join me as we briefly discuss the intents and overall design of the M113 engine.

What are Mercedes M113 Engines?

The Mercedes M113 engine is a V8, water-cooled, spark-ignition internal-combustion gasoline engine introduced by the then-DaimlerChrysler AG, now Mercedes-AMG GmBH in September 1997 for their E-Class vehicles, and later in the S-Class 220 series. This automobile engine family is used in the 200s and is based on the identical M116 V6 engine, which was introduced in 1998, then was later phased out in 2007 to make way for the new M273 and M156 AMG engine.

The M113 engine is meant to replace the aging 1989-produced M119 engine of the same brand. The standard M113 machines are produced in Untertürkheim, Germany, while the AMG versions are assembled in the Affalterbach, Germany, plant.

Mercedes M113 engines have aluminum engine blocks and aluminum SOHC cylinder heads with two spark plugs in each cylinder. The cylinder liners are made from the combination of Silicon and Aluminum, and the heads have three valves cylinder – two for the intake and one exhaust. Other M113 features include:

  • Fracture-split forged steel connecting rods.
  • Sequential fuel injection.
  • One-piece cast camshaft.
  • A magnesium intake manifold.

There are three versions that Mercedes made for the M113 engine with various displacements – 4.3, 5.0, and 5.4 L. Each of these versions is attached with different upgrades for their respective applications, which we will discuss later. The M113 was offered both with mechanical supercharging and without.

Engine Specifications and Design:

  • Production Run: 1998 – 2007
  • Cylinder Head Material: Aluminum
  • Cylinder Block Material: Aluminum
  • Configuration: V8
  • Bore: 89.9 mm (E43) and 97 mm (E50 and E55)
  • Stroke: 84.1 mm (E43 and E50) and 92 mm (E55)
  • Valvetrain: SOHC three valves per cylinder
  • Displacement: 4.3 L (4266 cc for E43), 5.0 L (4966 cc for E50), and 5.4 L (5439 cc for E55)
  • Compression Ratio: 10 (E43 and E50) 10.5 and 11 for E55
  • Weight: 362 lbs. (E43) and 377 lbs. (E50 and E55)
  • Maximum HP: 574 HP at 6,000 RPM
  • Maximum Torque: 590 lb-ft at 2,750 – 4,000 RPM

The Mercedes M113 engine is more technically related to the M112 V6 gasoline engine since both engines share the same cylinder bank angle of 90-degrees and uniform cylinder spacings of 106 mm. And that results in more efficient production, especially in the facility they occupy as well as the components they use.

The M133 cylinder block is made from aluminum with cast-in Silitec (Al-Si-alloy) cylinder liners and cylinder banks arranged in a ‘V’ configuration. It is integrated with sequential fuel injection, iron-coated aluminum pistons, magnesium dual-length intake manifold, and fracture-split forged steel connecting rods.

It has a light aluminum alloy cylinder head with a single overhead camshaft per cylinder bank; the camshaft is also the balancer shaft, the same as the M112 engine, and is driven by a double roller chain.

For each cylinder, the M113 engine has two intake valves and one exhaust valve, which were actuated by light metal roller rocker arms with hydraulic valve clearance compensation. Mercedes chose a single exhaust valve to result in a smaller surface exhaust passage that minimizes heat losses when cold and enables the catalytic converter to reach the operating temperature faster.

A thin-walled sheet metal exhaust manifold also contributes to this by absorbing only small amounts of heat. To add, on the crankshaft in the cylinder, a balancer shaft is placed that rotates inversely to the crankshaft at the same rate to equalize first-order rocking motions.

The M113 engine has two spark plugs arranged on the right and left of the exhaust valve for the combustion chamber. These valves are arranged in a symmetrical manner with a double ignition operation with time-shifted control to have fast and uniform combustion, higher tolerance for a lean mixture, greater safety against combustion misfiring, and promotes better exhaust gas recirculation.

The double ignition affects the piston action due to a higher heat load imposed on the piston, which is cooled by oil spray nozzles placed below the piston crown.

The 4966 cc E50 engine variant is optionally available with cylinder deactivation (ZAS), enabling two cylinders on each bank to shut down when the engine is running at a low load and speed not exceeding 3,500 RPM. The valves are also shut down, and the rocker arms are divided into two, and those parts can be disengaged from each other by a hydraulically actuated piston.

The ZAS provides a greater engine efficiency through smaller throttle losses, and higher compression rating as the cylinders are filled better.

The Mercedes M113 E43

This variant of the M113 engine was assembled by AMG, the performance division of the Mercedes. Compared to the usual Mercedes-Benz engines, the changes for the AMG include:

  • A double-fluted intake system.
  • A larger intake manifold.
  • A composite camshaft that was individually forged.
  • A better exhaust system with a modified muffler system and larger pipes to minimize exhaust gas back-pressure.

The bore and stroke of the E43 are 89.9 mm and 84.1, respectively. Its displacement is 4,266 cc, the smallest in this series, and was rated at 275 HP at 5,750 RPM with 295 lb-ft of torque at 3,000 RPM. The C43 AMG variant, however, was rated at a higher number with 302 HP at 5,850 RPM and 302 lb-ft of torque at 3,250 RPM.

Applications of M113 E43 engine:

  • 1997 – 2000 C 43 AMG
  • 1997 – 2002 E 430
  • 1998 – 2003 CLK 430
  • 1999 – 2001 ML 430
  • 1999 – 2006 S 430

The Mercedes M113 E50

The E50 stands in the middle in terms of displacement with 5.0 Liter. It has a bore and stroke of 97 mm and 84 mm, respectively. It was rated at 302 HP at 5,600 RPM with 339 lb-ft of torque at 2,700 to 4,250 RPM. The Active Cylinder Control variable displacement technology was offered optionally.

Applications of M113 E50:

  • 1998 – 2008 G 500
  • 1999 – 2006 S 500
  • 1999 – 2006 SL 500
  • 2000 – 2006 CL 500
  • 2001 – 2006 ML 500
  • 2002 – 2006 CLK 500
  • 2003 – 2006 E 500
  • 2004 – 2006 CLS 500
  • 2006 – 2007 R 500
  • 2008 – 2017 SsangYong Chairman W

The Mercedes M113 E55

The E55 is developed by the Mercedes-AMG and was the first car to carry the 55 AMG badge. It has the same 97 mm cylinder bore as the E50 but a longer piston stroke of 92 mm. It was rated at 362 HP at 5,500 RPM with 391 lb-ft of torque at 2,800 – 5,400 RPM.

Applications of M113 E55:

  • 1997 – 2000 C 55 AMG
  • 1998 – 2001 SL 55 AMG
  • 1998 – 2002 E 55 AMG
  • 2000 – 2002 S 55 AMG
  • 2000 – 2003 CLK 55 AMG
  • 2002 – 2006 CLK 55 AMG
  • 2001 – 2002 CL 55 AMG
  • 2002 – 2003 G 55 AMG
  • 2004 – 2010 SLK 55 AMG
  • 2006 – 2008 SLK 55 AMG Black Series
  • 2005 – 2007 C 55 AMG

The Mercedes M113 E55 Kompressor

M113 E55 is the supercharged and twin-intercooled version of the M113 engine; it is also the largest among the variants. It is referred to as the “M113K” – where K stands for Kompressor or supercharger. It has a Lysholm-type IHI supercharger positioned between the cylinder bank that provides a maximum boost pressure of 11.6 psi and has an integrated air-water charge intercooler.

The supercharger has two Teflon-coated aluminum shafts that rotate at 23,000 RPM, a maximum that pushes 4080 lbs. of air per hour directly into the combustion chambers. However, the scroll compressor only operates at particular engine speeds and load conditions to minimize fuel consumption activated by a separate poly-V-belt and electromagnetic coupling.

Other changes in this engine include:

  • A restyled fuel system
  • A dual-pipe exhaust system with switchover valve and larger diameter tailpipes for reduced exhaust gas back-pressure
  • Revamped engine management system
  • Optimized cylinder heads
  • A twin-spring assembly for the valve train to increase maximum engine speed to 6,100 RPM
  • A revised oil supply system (sump, catch tray, and pump) and a separate oil cooler in the right-hand wheel arch
  • Forged connecting rods
  • A precision-balanced crankshaft
  • Redesigned pistons
  • Reinforced crankcase with stiffening ribs and side bolts

Many AMG enthusiasts argue that the M113K was the last of the excellent Kompressor engine used, excluding the Mercedes SLR McLaren. And unfortunately, Mercedes-AMG replaced this model with the new naturally aspirated 6.2 L V8, which marks the transition from 55 AMG to 63 AMG. Even though the 6,2 L M156 engine has a higher peak power, many were disappointed by the lack of decent torque in the new design.

Applications of the Mercedes M113 E55K:

  • 2003 – 2006 CL 55 AMG
  • 2002 – 2006 S 55 AMG
  • 2002 – 2008 SL 55 AMG
  • 2003 – 2006 E 55 AMG
  • 2004 – 2006 CLK DTM AMG
  • 2004 – 2011 G 55 AMG
  • 2004 – 2006 CLS 55 AMG

Engine Tuning, Upgrades, and Modifications

Mercedes released a supercharged version of the M113, also called M113K; they also designed one made exclusively for the Mercedes-Benz SLR McLaren. With that being said, if you desire to have additional mod or tuning, you can do it by upgrading your camshafts. This change dramatically enhances the HP and the torque.

You can also throw in some exhaust performance parts and flash the ECU. In this way, you can gain at least 30% more power on your engine.

Problems Surrounding Mercedes M113 Engines:

Apart from being the top-notch engine that Mercedes produced, it is also one of the best in the industry. Impressive as it is by the numbers. However, even those praises do not make the M113 a perfect engine, so it has some weaknesses and issues that you might encounter with this engine.

The supercharged version, 5.4 L M113K, is equipped with intercoolers that are unique to this engine. As such, this issue only affects higher-performance machines. A brief description of the intercooler is that intercoolers are responsible for cooling pressurized air. Without intercoolers, the intake air temperature will rise drastically and prompts the computer to disable the supercharger.

The issue with M113 is the failure of the intercooler pump. If the pump fails, it causes the intercooler system to run under the capacity or shuts down. When this happens, the intake air temperature rises and leads to worse engine performance. Once the air got too hot, the computer will shut down the supercharger.

The next issue focuses more on the effects of the age and mileage of the M113 engine – oil leaks. However, this is not exclusive to the M113 as it affects many machines.

The rubber seals and gaskets deteriorate over time and begin to crack, which happens at the M113 rear main seal.

The rear primary seal main purpose is to seal the crankshaft where it connects to the transmission. When cracks develop, the oil began to leak, which becomes worse and worse. This is not an urgent problem, but you might want to replace the seals before the leaking becomes flooding and affect the total performance of the engine.

This issue can be noticed by the visible leaks towards the rear of the engine bay; valve cover gasket leaks might show symptoms like burning oil smells and light smoke.

The last is not an issue but more of a preventive replacement. Since the M113 V8 runs on two spark plugs per cylinder to a total of 16 spark plugs, they need to be replaced because they are simply a standard maintenance item.

These spark plugs are essential to a smoother running engine. Worn-down spark plugs can no longer ignite the cylinder’s air-fuel mix, which generally leads to misfires and drivability issues. This issue is much more applied to the supercharged version due to its high boost abilities that cause high cylinder pressures that put more stress on ignition components. Poser loss can be a telltale sign, but it is hard to notice unless multiple cylinder misfiring happens.

Always remember that any engine needs quality engine oil and fuel.

Summary

Mercedes really took off and change the way we see engines. The innovation that they integrated in the 1920s was revolutionary and deserved wild recognition for that effort. A style that not only we see on tracks but also on everyday cars – the supercharger. To them, I give them the utmost credit.

And the last leg of that innovation is the M113 family. Many consider this as the last great Kompressor engine. It has the right balance of aggressive power and torque, quick response, efficient combustion due to the overwhelming number of spark plugs, and intricate details that spearhead different technology in internal combustion. It is lighter than its M119 predecessor, has lower exhaust emissions, and is shorter, making it a better fit even with a larger displacement.

It is a solid engine overall; a block that can withstand 400 HP is no easy feat – even touching the 550 mark – which they did. Given the old age of this engine, it is crucial to maintain it so issues won’t get in the way.

To add, M113 engines are getting rarer and rarer every day, so if you own one, habitually check your machine for any service that it needs.

I hope that this brief and straightforward discussion helped you understand the M113 engine design, issues, applications, capabilities, features, reliability, and overall impact on the automotive industry.

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