M104 E320 engine


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An inline 6-cylinder engine with the capacity of 3.2 liters. There was also an AMG-version 3.6-liter. The engine has two camshafts and four valves per cylinder.

All engines without the ignition distributor intake camshaft were equipped with the clutch with an electro-hydraulic actuator for the variable valve timing. Phase changes occur without a smooth adjustment – only two extreme positions.

M104 E320 engine specs

Manufacturer Stuttgart-Bad Cannstatt Plant
Also called M104
Production years 1991-1998
Cylinder Block Material Cast Iron
Fuel system Fuel injection
Configuration Inline
Number of cylinders 6
Valves per cylinder 4
Stroke, mm 84.0
Bore, mm 89.9
Compression Ratio 9.2 – 10
Displacement, cc 3199
Power, hp 220-231/5500-5800
Torque, lb-ft 229-232/3750-4100
M105 engine Oil 0W-30, 0W-40, 5W-30, 5W-40, 5W-50, 10W-40, 10W-50, 15W-40, 15W-50
Oil capacity, liter 7.5
Oil change interval, mile 6,000
Fuel consumption,  L/100 km

E320 W124:

city – 14.0
highway – 8.5
combined – 11.0



  • Mercedes-Benz E 320 W124
  • Mercedes-Benz E 320 W210
  • Mercedes-Benz 300 SE W140
  • Mercedes-Benz S 320 W140
  • Mercedes-Benz SL 320 R129
  • SsangYong Chairman W
  • SsangYong Rexton

M104 engine problems and Reliability

The engine was very good, well-balanced. But for all its reliability it had several birth defects:

  1. Oil leaking. Oil leaks from gaskets under cylinder head cover and oil filter.
  2. Engine overheat. If you notice that your engine began to overheat, check the condition of the radiator and the viscous coupling.
    If you use high-quality oil, gasoline and make regular maintenance service, M104 will run a long time. This engine is one of the most reliable Mercedes-Benz engines.

Uncontinuous oil leaking?! That is a huge problem! Fortunately we know how to help. Read this top 10 radiator stop leak products.

Headache pain of the Mercedes M104 engine is overheating of the rear of the cylinder head and its distortion. You can not escape this because the problem relates to its construction.

Another serious problem may arise with a bad (not proper) operation of this engine. Council urges timely change the oil in the engine, and use only high-quality oil.

It is necessary to monitor the integrity of the main cooling fan. If there is even a slight deformation of the fan blades you should immediately replace it.

  M104 E32 engine modifications

  1. M104.990 (1991 – 1993 onwards) – the first version of the 231 hp at 5800 rev / min, 310 Nm of torque at 4100 rev / min. The compression ratio is 10. Sets the engine at the Mercedes-Benz 300 SE / SEL W140.
  2. M104.991 (1993 – 1998 onwards) – analog of the restyled M 104,990 for the Mercedes-Benz SL320 R129.
  3. M104.992 (1992 – 1997 onwards) – analog of the M104,991, the compression ratio was reduced to 9.2, the power of 220 hp at 5500 rev / min, 310 Nm of torque at 3750 rev / min. Sets for Mercedes-Benz 320 E W124, E320 W124.
  4. M104.994 (1993 – 1998 onwards) – analog of the M104,990 with another intake manifold, the power of 231 hp at 5600 rev / min, torque of 315 Nm at 3750 r / min. Fits on Mercedes-Benz S 320 W140.
  5. M104.995 (1995 – 1997 onwards) – Power 220 hp at 5500 rev / min, 315 Nm of torque at 3850 rev / min. Fits on Mercedes-Benz E 320 W210.

Mercedes M104 engine tuning

Compressor. Turbo

Alteration of 3.2 liters into 3.6 liters. AMG is one of the first things the owner of M104 E32 has, however, for the implementation of such projects you need to replace the crankshaft, connecting rods, pistons, cylinder head to modify, replace camshafts and injectors, pumps, and other stuff. It is much easier or just buy the engine Mercedes-Benz M104 E36 AMG, or set the boost to the standard engine and get more power.

For this purpose is suitable any modest compressor kit (such as the Eaton M62), inflated to 0.5 bar standard piston thick cylinder head gasket, with the injectors 350 cc and more productive fuel pump outlet 3, set the MegaSquirt / VEMS obtain ~ 300 hp. Instead of the compressor can be found Mossellman turbo kit with a similar pressure to obtain the same power.

If such a return seems low, you need to either buy a more powerful engine and a modern Mercedes, or pay attention to the Turbo Bandit kits, after the installation of the which the car won’t look like a city auto.

First Start w201 M104 3.2 swap

Dan Hoffman

Dan is a co-founder of Engineswork. He knows everything about internal combustion engines. Ask your questions in comments down below this article - he will be glad to help you anytime.

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