Mercedes-Benz M111 Specifications
| Engine Model: Mercedes-Benz M111 |
| Engine Type: 4-cycle 4-cylinder DOHC 16-valve liquid-cooled gasoline |
| Total Displacement: 110-140 cu.in (1.79-2.29 L) |
| Rated Engine Power: 122-197 Hp (90-145 kW) at 5500 rpm |
| Fuel System Type: Multi-point fuel injection |
____________________________________________________________________________________
The Mercedes-Benz M111 engine family represents a
generation of straight-four powerplants produced from 1992 through 2003, serving
as the successor to the M102 series. Designed as a modern, high-revving power
unit, the M111 introduced a consistent architecture featuring a cast-iron
cylinder block combined with an aluminum alloy cylinder head utilizing dual
overhead camshafts (DOHC) and four valves per cylinder.
This configuration allowed for improved volumetric efficiency and refined power
delivery across the engine speed range. The family encompassed naturally
aspirated and supercharged variants, the latter marketed under the Kompressor
designation, which employed Eaton M45 or M62 positive-displacement
superchargers.
Production versions spanned displacements of 1.8 liters (110 cu.in) , 2.0 liters
(122 cu.in), 2.2 liters (134 cu.in), and 2.3 liters (140 cu.in), with the engine
being installed across a broad array of Mercedes-Benz passenger cars, the SLK
roadster, the Sprinter van, and later appearing in SsangYong vehicles under
licensing agreements. A significant evolution occurred around 2000 with the
introduction of reinforced block architecture, individual coil-on-plug ignition,
and upgraded internal components, enhancing durability and emissions compliance.
Engine Power and Torques
1.8L (M111.921): 122 hp (90 kW) at 5,500 rpm; 170 Nm torque.
2.0L (M111.94x): 136 hp (100 kW) at 5,500 rpm; 190 Nm torque.
2.0L Kompressor (M111.94x ML): 180-192 hp (132-141 kW).
2.2L (M111.96x): 150 hp (110 kW); 210 Nm torque.
2.3L (M111.97x): 143-150 hp (105-110 kW); 220 Nm torque.
2.3L Kompressor (M111.97x ML): 193-197 hp (142-145 kW); 280 Nm.
The M111 engine family operates on a four-stroke Otto cycle with a straight-four
cylinder configuration. The cylinder numbering follows the conventional order
from the front of the engine to the flywheel end. The engine orientation is
longitudinal in most passenger car applications and transverse in certain
models. The firing order is 1-3-4-2. The valvetrain comprises dual overhead
camshafts driven by a single-row roller chain from the crankshaft, with a
secondary chain driving the opposite camshaft. Hydraulic lifters are employed
throughout the series, eliminating the requirement for manual valve clearance
adjustments.
The fuel system evolved during production: early versions utilized PMS
(Piezoelectric Mixture System) electronic fuel injection, followed by HFM (Hot
Film Mass) management, and later models adopted ME (Motronic Engine) or Siemens
SIM4 engine control units. All systems are multi-point sequential fuel
injection. The induction system on naturally aspirated engines uses a plastic
intake manifold with variable-length intake runners on certain variants, while
Kompressor engines incorporate an intercooler downstream of the supercharger to
reduce intake air temperature.
The cylinder block is constructed from gray cast iron,
providing exceptional rigidity and bore stability under thermal and mechanical
loads. The block features a deep-skirt design with the crankcase extending below
the crankshaft centerline, contributing to structural stiffness and reduced
vibration. Cylinder bores are machined directly into the iron substrate without
the use of separate liners, finished with a plateau honing process to optimize
oil retention and ring seating.
Bore diameters vary according to displacement: the 1.8-liter engine uses an 85.3
mm (3.358 in) bore; the 2.0-liter and 2.2-liter share an 89.9 mm (3.539 in)
bore; and the 2.3-liter employs a 90.9 mm (3.579 in) bore. The block
incorporates five main bearings with steel-backed, aluminum-tin-silicon bearing
shells. Main bearing cap attachment uses four bolts per cap, with the central
cap receiving additional transverse bolts on reinforced EVO versions.
Coolant passages surround each cylinder in a full-length water jacket
configuration, with siamesed bores on the 2.3-liter variant to accommodate the
larger cylinder spacing. The block casting includes integrated oil galleries
supplying pressurized lubricant to the crankshaft main bearings, connecting rod
bearings, and the cylinder head via external oil feed pipes.
The cylinder head is manufactured from aluminum-silicon
alloy, heat-treated to achieve required hardness and dimensional stability. The
cross-flow design positions the intake ports on the front-facing side and
exhaust ports on the rear, optimizing thermal management. Combustion chambers
are of the pent-roof configuration with four valves per cylinder arranged in a
splay pattern.
The DOHC arrangement comprises an intake camshaft and an exhaust camshaft, each
supported by five bearing caps integrated into the cam carrier assembly. Valve
diameters differ by displacement and aspiration: intake valves range from 32.0
mm to 34.5 mm (1.260 in to 1.358 in), while exhaust valves measure between 29.0
mm and 30.5 mm (1.142 in and 1.201 in). Valve stems are 6 mm (0.236 in) in
diameter with hard chrome plating for wear resistance.
Valve seats are sintered metal inserts, with the intake seats using a ferrous
alloy and exhaust seats employing a nickel-based heat-resistant material. Valve
guides are powdered metal inserts. Hydraulic lash adjusters are positioned
directly above the valve stems, actuated by roller finger followers that reduce
friction and allow for high engine speeds. The camshaft drive system
incorporates a hydraulic chain tensioner maintaining constant tension on the
primary and secondary chains.
All M111 engines utilize multi-point electronic fuel
injection with individually controlled injectors located in the intake ports,
directing fuel toward the intake valves. Fuel pressure is regulated by a
vacuum-referenced pressure regulator maintaining a constant differential
pressure across the injectors, with system pressure set at 3.5 bar (50.8 psi).
Early PMS systems employed a mass airflow sensor and a distributor-based
ignition system.
HFM systems integrated the air mass meter, ignition control, and fuel injection
into a single management unit with individual coil packs introduced on later
variants. ME-Motronic systems, introduced progressively from 1997, provided full
sequential injection and coil-on-plug ignition. The EVO update from 2000
standardized Siemens SIM4 engine management with wideband oxygen sensor
feedback, enabling Euro IV emissions compliance.
Fuel injectors are high-impedance units with a static flow rate between 180 and
240 cc per minute (10.98 to 14.64 cu.in per minute) depending on engine output.
The fuel system on Kompressor engines incorporates a bypass valve to recirculate
supercharger outlet pressure during closed-throttle conditions, preventing
compressor surge.
The lubrication system is a fully pressurized wet-sump
design incorporating a gear-type oil pump mounted on the crankshaft nose within
the timing chain cover. The pump draws oil from a stamped steel sump through a
strainer-type pickup. System pressure is regulated by a spring-loaded relief
valve set between 3.5 and 4.5 bar (50.8 and 65.3 psi) depending on engine
temperature and speed.
The oil filter is a full-flow spin-on canister type with an integrated bypass
valve. Oil galleries are cast into the cylinder block and cylinder head,
delivering lubricant to the main bearings, connecting rod bearings, camshaft
bearings, and hydraulic lifters. Piston cooling is achieved through oil jets
directed at the underside of the piston crowns, these jets being integral to the
cylinder block on later EVO engines.
Oil capacity varies by sump configuration: passenger car applications hold
approximately 5.5 liters (5.8 qt), while Sprinter and off-road variants with
deeper sumps hold up to 6.5 liters (6.9 qt). Recommended oil viscosity ranges
from SAE 5W-30 to 10W-40 with API SJ or higher classification.
The cooling system operates on a pressurized
closed-loop principle with a belt-driven water pump mounted on the front of the
cylinder block. The pump circulates coolant through the cylinder block water
jacket, cylinder head, and a cross-flow radiator with a single electric cooling
fan. A wax-element thermostat located in the coolant return housing controls
flow to the radiator, with an opening temperature of 87°C (189°F).
System pressure is regulated by a spring-loaded cap at 1.4 bar (20.3 psi),
raising the boiling point to approximately 126°C (259°F). Coolant composition is
specified as ethylene glycol-based antifreeze mixed with demineralized water in
a 50:50 ratio. The heater circuit draws coolant from the cylinder head via a
dedicated port, passing through the heater core and returning to the water pump
inlet. Kompressor engines incorporate an additional coolant circuit for the
supercharger intercooler when equipped with a liquid-to-air charge cooling
system.
The ignition system on early M111 engines utilized a
distributor with a Hall effect sensor, later replaced by individual ignition
coils mounted directly over each spark plug. Spark plugs are specified with a
gap of 0.8 mm (0.031 in) for naturally aspirated engines and 0.7 mm (0.028 in)
for Kompressor variants. The EVO engines introduced iridium-tipped spark plugs
with extended service intervals. The exhaust system incorporates a close-coupled
catalytic converter on post-1996 models, with lambda sensors positioned before
and after the catalyst for closed-loop fuel control.
The positive crankcase ventilation system routes blow-by gases from the cylinder
head cover to the intake manifold through an oil separator. The vacuum system
supplies the brake booster, exhaust gas recirculation valve on certain markets,
and the supercharger bypass actuator on Kompressor engines. Engine mounts are
hydraulically damped units on most applications to reduce vibration transmission
to the vehicle structure.
Length measured from the front of the crankshaft pulley
to the flywheel mounting face is 590 mm (23.23 in). Width across the cylinder
head and intake manifold ranges from 520 to 560 mm (20.47 to 22.05 in) depending
on intake configuration. Height from the oil sump mounting flange to the top of
the cylinder head cover is 650 mm (25.59 in).
The engine dry weight without accessories is 145 kg (319.7 lb) for naturally
aspirated variants. Kompressor engines add 15 kg (33.1 lb) due to the
supercharger, intercooler, and additional bracketry. The cast-iron block
contributes significantly to the overall mass, accounting for 75 kg (165.3 lb)
of the total assembly.
Oil change intervals are specified at 10,000 km (6,214
mi) or 12 months under normal operating conditions, reduced to 5,000 km (3,107
mi) for severe duty applications. Spark plug replacement intervals are 60,000 km
(37,282 mi) for conventional copper-core plugs and 100,000 km (62,137 mi) for
iridium plugs used in EVO engines. Coolant replacement is recommended every four
years or 80,000 km (49,710 mi) using Mercedes-Benz-approved antifreeze.
Air filter element replacement occurs at 30,000 km (18,641 mi) intervals or more
frequently in dusty environments. Drive belt inspection is required every 20,000
km (12,427 mi), with replacement every 80,000 km (49,710 mi) for the serpentine
belt driving auxiliary components.
Camshaft drive chain inspection is not routinely scheduled; however, chain
tensioner replacement is recommended at 150,000 km (93,206 mi) if chain noise
becomes evident. Valve clearances require no maintenance due to the hydraulic
lash adjuster system. Fuel filter replacement is specified every 60,000 km
(37,282 mi).
Cylinder head bolts follow a multi-stage angular
tightening procedure. Initial torque for M11 x 1.5 bolts is 30 Nm (22 lb-ft),
followed by a 90-degree rotation, then a second 90-degree rotation after a brief
settling period. Main bearing cap bolts for M10 x 1.25 fasteners receive 30 Nm
(22 lb-ft) plus 90 degrees. Connecting rod cap bolts for M8 x 1.0 fasteners are
torqued to 20 Nm (15 lb-ft) plus 90 degrees.
Camshaft bearing cap bolts for M6 fasteners receive 9 Nm (80 lb-in). Intake
manifold to cylinder head bolts for M7 fasteners are torqued to 15 Nm (11
lb-ft). Exhaust manifold to cylinder head bolts for M8 fasteners receive 25 Nm
(18 lb-ft). Flywheel to crankshaft bolts for M12 fasteners are torqued to 110 Nm
(81 lb-ft) plus 90 degrees. Crankshaft pulley bolt for M16 fastener receives 200
Nm (148 lb-ft) plus 90 degrees.
Oil filter housing bolts for M8 fasteners are torqued to 25 Nm (18 lb-ft).
Thermostat housing bolts for M6 fasteners receive 9 Nm (80 lb-in). Water pump
mounting bolts for M7 fasteners are torqued to 15 Nm (11 lb-ft). Knock sensor
bolts for M8 fasteners receive 20 Nm (15 lb-ft). All torque specifications
assume clean, lightly oiled threads unless specified otherwise by Mercedes-Benz
service documentation.
The M111 engine was installed across numerous
Mercedes-Benz models. In the W124 chassis, the 2.0-liter M111.940 and 2.2-liter
M111.960 powered the E200 and E220 from 1993 to 1996. The W202 C-Class received
the 1.8-liter M111.920 in the C180, the 2.0-liter M111.940 and M111.945 in the
C200, the 2.2-liter M111.960 in the C220, and the 2.3-liter M111.973 and
M111.974 in the C230 and C230 Kompressor.
The W210 E-Class utilized the 2.0-liter M111.942 in the E200, the 2.3-liter
M111.970 in the E230, and the 2.3-liter M111.973 Kompressor in certain markets.
The R170 SLK roadster employed the 2.0-liter M111.943 and M111.944 Kompressor in
the SLK200, and the 2.3-liter M111.973 and M111.983 Kompressor in the SLK230.
The W163 ML230 utilized the naturally aspirated 2.3-liter M111.973.
The Sprinter van series 901 and 903 received the 2.3-liter M111.978 and
M111.979. Following Mercedes-Benz licensing agreements, the M111 also appeared
in SsangYong models including the Musso, Korando, and Chairman under the
M111.970 and related designations.
____________________________________________________________________________________
| Car Engines Technical Specifications |
| Small Engines Technical Specifications |
| Industrial Engines Technical Specifications |
| Outboard Engines Technical Specifications |
