The

Mercedes-Benz Mercedes-Benz (), commonly referred to as Mercedes and sometimes as Benz, is a German luxury and commercial vehicle automotive brand established in 1926. Mercedes-Benz AG (a Mercedes-Benz Group subsidiary established in 2019) is headquartere ...

M103 is a straight-6 15 degrees,

crossflow cylinder head A crossflow cylinder head is a cylinder head that features the intake and exhaust ports on opposite sides. The gases can be thought to flow across the head. This is in contrast to reverse-flow cylinder head designs that have the ports on the same ...

with an inclination to the right,

automobile A car or automobile is a motor vehicle with wheels. Most definitions of ''cars'' say that they run primarily on roads, seat one to eight people, have four wheels, and mainly transport people instead of goods. The year 1886 is regarde ...

engine produced from 1984 to 1997. It is a single overhead cam design with 2 valves per cylinder. The M103 was replaced by the M104 starting in 1989. The bore spacing on the M103 engine is 97 mm. This engine received several updates over the years of production, one of the updates was a change from a spherical combustion chamber to a "heart shaped" combustion chamber.

3.0 L

The 103.980 engine of uses the CIS-E (

Continuous Injection System Manifold injection is a mixture formation system for internal combustion engines with external mixture formation. It is commonly used in engines with spark ignition that use petrol as fuel, such as the Otto engine, and the Wankel engine. In a mani ...

- Electronic). ;Specifications *

Engine power Engine power is the power that an engine can put out. It can be expressed in power units, most commonly kilowatt, pferdestärke (metric horsepower), or horsepower. In terms of internal combustion engines, the engine power usually describes the ' ...

@ 5700 rpm: with

catalyst Catalysis () is the process of increasing the rate of a chemical reaction by adding a substance known as a catalyst (). Catalysts are not consumed in the reaction and remain unchanged after it. If the reaction is rapid and the catalyst recyc ...

, without catalyst *

Torque In physics and mechanics, torque is the rotational equivalent of linear force. It is also referred to as the moment of force (also abbreviated to moment). It represents the capability of a force to produce change in the rotational motion of th ...

@ 4400 rpm: (with catalyst), without catalyst * Bore and stroke: * Compression ratio: 9.2:1 * Redline: 6200 rpm *

Firing order The firing order of an internal combustion engine is the sequence of ignition for the cylinders. In a spark ignition (e.g. gasoline/petrol) engine, the firing order corresponds to the order in which the spark plugs are operated. In a diesel engi ...

: 1-5-3-6-2-4 * Lubrication system: pressure circulation * Oil capacity: * Coolant capacity: * Number of valves: 1 intake, 1 exhaust with V-shaped overhead configuration * Valve operation: 1 top camshaft. * Camshaft drive: simple roller-type chain * Starter motor: 1.5 kW electrical motor; since Jan 1988: 1.7 kW *

Ignition system An ignition system generates a spark or heats an electrode to a high temperature to ignite a fuel-air mixture in spark ignition internal combustion engines, oil-fired and gas-fired boilers, rocket engines, etc. The widest application for spark i ...

: electronic ignition system. * Recommended fuel octane: 91 RON/MON (96 RON) (86 MON). This engine can be found in the

W124 The Mercedes-Benz W124 is a range of mid-size cars made by Daimler-Benz from 1984 to 1997. The range included numerous body configurations, and though collectively referred to as the W-124, official internal chassis designations varied by body st ...

( 300E), W126 ( 300SE / 300SEL), R107 (

300SL The Mercedes-Benz 300 SL (chassis code W 198) is a two-seat sports car which was produced by Mercedes-Benz as a gullwinged coupe (1954–1957) and roadster (1957–1963).Werner Oswald: ''Mercedes-Benz Personenwagen 1945–1985''. Motorbuch Ve ...

), R129 (

), W463 ( 300GE), and Isdera Spyder 036i.

2.6 L

The smaller 103.940 engine of also used the CIS-E engine management system. ;Specifications *

@ 5800 rpm: with

, without catalyst *

@ 4600 rpm: with catalyst, without catalyst. * Bore and stroke: * Compression ratio: 9.2:1 * Redline: 6200 rpm *

: 1-5-3-6-2-4 * Lubrication system: pressure circulation * Oil capacity: * Coolant capacity: * Camshaft drive: simple roller-type chain * Number of valves: 1 intake, 1 exhaust with V-shaped overhead configuration * Valve operation: 1 top camshaft * Starter motor: 1.5 kW electrical motor; since Jan 1988: 1.7 kW *

: electronic ignition system. The only mechanical differences from the M103 3.0 L to the M103 2.6 L were the smaller bore and intake valves, with a slightly different airbox. The CIS-E components between 2.6 and 3.0 variants are all shared for any given model year with the exception of the ECU making engine swaps from 2.6 to 3.0 virtually bolt-in. This engine can be found in the W201 ( 190E 2.6),

( 260E / 300E 2.6) and W126 ( 260SE). {{DEFAULTSORT:Mercedes-Benz M103 Engine M103 Straight-six engines