Mercedes-Benz M104 engine

This article needs additional citations for verification. Please help by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources:  –  ·  ·  · scholar · JSTOR (January 2021) (Learn how and when to remove this template message)

M104
Overview
Manufacturer	Mercedes-Benz AG
Production	1989-99
Layout
Configuration	Straight-6 (Except M104.900, refer VW VR6)
Displacement	2.8 L; 170.8 cu in (2,799 cc) M104.94x 3.0 L; 180.6 cu in (2,960 cc) M104.98x 3.2 L; 195.2 cu in (3,199 cc) M104.99x
Block material	Cast iron
Head material	Aluminium
Valvetrain	DOHC 4 valves x cyl. with VVT
Compression ratio	9.2:1, 10:1 and 10.5:1 on AMG models
Combustion
Fuel system	Bosch KE-Jetronic electronically controlled, mechanical fuel injection (CIS-E)/Bosch Motronic integrated electronic injection/ignition (HFM)
Management	Electronic
Fuel type	Gasoline
Oil system	Wet sump
Cooling system	Water cooled
Output
Power output	193–280 PS (142–206 kW; 190–276 hp) SAE
Torque output	265–385 N⋅m (195–284 lb⋅ft) at 4600 rpm M104.98x
Chronology
Predecessor	M 103
Successor	M 112

The Mercedes-Benz M104 is a straight-6 automobile engine produced from 1989 through 1999. It has a double overhead cam design with 4 valves per cylinder, and used a crossflow cylinder head. It replaced the M103 and was replaced by the M112 V6 starting in 1997. The M104 continued in production until 1999 where its last use by Mercedes-Benz was in the W140 chassis. The bore spacing on all M104 engines is the same as the M103 engine at 97 mm.

2.8 L M104.900[]

As Mercedes needed a compact 6-cylinder for their Vito, they agreed with Volkswagen to use their VR6 engine, which they then designated M104.900.^[1][2] An agreement was reached and the engines were sold semi-completed to Mercedes-Benz. This version is unrelated to other engines designated M104. Only the engine cover and aircleaner housing is by Mercedes-Benz.

3.0 L M104.98x[]

This 3.0 L (2,960 cc) 24v was introduced as a sports car resp. top model completing the line-up of M103 12V engines. The M104 featured dual overhead camshafts and four valves per cylinder. The M103 and M104.98x were later replaced by the 2.8-litre and 3.2-litre versions of the M104.

The 3.0 L (2,960 cc) M104 featured KE-Jetronic fuel injection, cylinder specific ignition-timing, variable valve timing and under-piston cooling jets.

Specifications

• Engine power @ 6400 rpm: 217 to 228 hp (162 to 170 kW; 220 to 231 PS)^[3] (without catalytic converter)
• Torque @ 4600 rpm: 265 N⋅m (195 lb⋅ft) (without catalytic converter)
• Bore and stroke: 88.5 mm × 80.2 mm (3.48 in × 3.16 in)
• Compression ratio: 10:1

Applications

• 1989–1992 C124 300 CE-24
• 1989–1993 R129 300SL-24
• 1990–1993 W124 300 E-24
• 1990–1993 S124 300 TE-24

2.8 L M104.94x[]

In 1993, two capacities replaced the 3.0 litre: a 2.8 L; 170.8 cu in (2,799 cc) replaced the old single-cam M103 engine and the 3.2 litre M104.99x replaced the double-cam M104.98x.

Specifications for 2.8 L

• Engine power @ 5500 rpm: 142 kW (193 PS; 190 hp)
• Torque @ 3750 rpm: 270 N⋅m (199 lb⋅ft)
• Bore and stroke: 89.9 mm × 73.5 mm (3.54 in × 2.89 in)
• Lubrication system: pressure circulation
• Oil capacity: 7.5 litres (2.0 US gal; 1.6 imp gal)
• Coolant capacity: 9 litres (2.4 US gal; 2.0 imp gal)
• Camshaft drive: duplex roller chain
• Starter motor: 1.7 kW electrical motor
• Ignition system: ignition mapping control

Applications

• W202 C280
• W210 E280
• 1993–1994 W124 280 E, 300 E 2.8
• 1994–1996 W124 E 280
• 1993–1998 W140 300 SE 2.8, S 280

3.2 L M104.99x[]

For the 3.2 L (3,199 cc), the compression ratio is the same 10.0:1 on all W210, R129, and W140 but it did differ from 9.2:1 to 10.0:1 on W124 (M104.992).^[4]

Specifications

• Engine power @ 5500 rpm: 162 kW (220 PS; 217 hp)
• Torque @ 3750 rpm: 310 N⋅m (229 lb⋅ft)
• Bore and stroke: 89.9 mm × 84 mm (3.54 in × 3.31 in)
• Compression ratio: 9.2:1 to 10.0:1
• Intake valves: 35 mm (1.4 in)
• Exhaust valves 31 mm (1.2 in)
• Starter motor: 1.7 kW electrical motor
• Ignition system: electronic ignition system

Applications

• Mercedes-Benz
  • 1993–1994 W124 300 E, 320 E
  • 1994–1996 W124 E 320
  • 1995–1997 W210 E320
  • 1991–1993 W140 300 SE, 300 SEL
  • 1993–1999 W140 S320
  • 1994–1998 R129 SL 320
  • W463 G320
• Roewe
  • 2011–2017 W5
• SsangYong
  • 1997-2006 Chairman
  • Korando
  • Kyron
  • 1993–1999 Musso
  • 2001–2006 Rexton Y200

AMG 3.4 L[]

There were 3.4 L conversions done to the 3.0 L M104.980 by AMG, prior to their formal cooperation with Daimler Benz.

AMG developed a 3.4 L M104 that was used principally in the 300E AMG 3.4, AMG 3.4 CE and 300TE-3.4 AMG (Mercedes-Benz W124) vehicles, produced between 1988-1993. A few of these engines were originally installed in the SL 3.4 AMG.

Specifications for AMG 3.4 L

• Engine power @ 6500 rpm: 200 kW (272 PS; 268 hp)
• Torque @ 4500 rpm: 268 N⋅m (198 lb⋅ft)
• Bore and stroke: 91.5 mm × 84 mm (3.60 in × 3.31 in)
• Lubrication system: pressure circulation
• Oil capacity: 7.5 litres (2.0 US gal; 1.6 imp gal)
• Coolant capacity: 9 litres (2.4 US gal; 2.0 imp gal)
• Starter motor: 1.7 kW electrical motor
• Ignition system: Bosch KE-Jetronic (CIS-E) injection

AMG 3.6 L M104.941/M104.992[]

There were 3.6 L conversions done to both the M103 and M104 by Brabus, among others.

AMG developed a 3.6 L; 220.1 cu in (3,606 cc) M104 that was used in the W202 C36 AMG (W202) from M104.941, the W124 E36 AMG (W124) from M104.992, the E36 AMG (W210), and the G36 AMG (W463) vehicles.

The AMG 3.6 M104 was rated at 276 hp (206 kW; 280 PS) at 5,750 rpm and 284 lb⋅ft (385 N⋅m) of torque at 4,000 rpm using the HFM engine management system. Bore and stroke is 91 mm × 92.4 mm (3.58 in × 3.64 in) with a compression ratio of 10.5. AMG later conceded that since the engine was hand modified, power outputs could vary slightly from 276 to 287 hp (206 to 214 kW; 280 to 291 PS).

The boost in displacement was obtained by boring the 2.8 litre M104 block by 2.1 mm (0.083 in) and using a highly modified version of the crankshaft from the 3.5L OM603 to increase throw by 18.9 mm (0.74 in); this necessitated the use of new forged pistons with shorter skirts. A larger intake crossover pipe, free-flowing exhaust, a unique intake camshaft, minor changes to the cylinder head, and modifications to the HFM fuel computer also contribute to the increase in power.

Ssangyong of South Korea made a 3.6 litre variant of M104 inline-six engine based on the 2.8 litre model, producing 248 hp (185 kW; 251 PS), for its Chairman model, a full-size luxury sedan.

Turbo Conversions[]

Turbocharger kits were offered for both the M103 and M104 engines by Hexagarage.com, Turbo Technics, Mosselman, Lotec, MAD Modify, Turbobandit and other tuners. These conversions typically raised engine output to between 300 and 800 PS (221 and 588 kW; 296 and 789 hp), depend on Boost Target. During the 1990s UK customers were able to buy new vehicles equipped with a Turbo Technics conversion directly from Mercedes dealer Hughes of Beaconsfield (limited run of 75 conversions). Today turbocharger kits for M103-M104 engines are available from later tuners in Europe and Asia.

References[]

Notes[]