Engine Mercedes M103 E26

The Mercedes M103 E26 engine was developed in 1985 to replace the ancient M123 engine. The M103 E30 served as the basis for the creation of a 2.6-liter power unit, the cylinder diameter of which was reduced to 82.9 mm.

The R6-family includes: M103 E26, M103 E30, M104 E28, M104 E30, M104 E32, M256 E30.

The cylinder head from the M103 E30 is adapted for the E26, the diameter of the intake valves is reduced from 43 mm to 40 mm, the exhaust valves from 39 mm to 35 mm. Fuel injection system – mechanical injection. The timing drive uses a single row chain that is subject to tension. Fuel supply system – KE-Jetronic.


Production years 1985-1993
Displacement, cc 2597
Fuel system KE-Jetronic
Power output, hp 160 – 165
Torque output, Nm 220 – 230
Cylinder block cast iron R6
Block head aluminum 12v
Cylinder bore, mm 82.9
Piston stroke, mm 80.2
Compression ratio 9.2
Features no
Hydraulic lifters yes
Timing drive chain
Phase regulator no
Turbocharging no
Recommended engine oil 5W-40
Engine oil capacity, liter 6.0
Fuel type petrol
Euro standards EURO 0/1
Fuel consumption, L/100 km (for 190 E W201)
— city
— highway
— combined
Engine lifespan, km ~450 000

Disadvantages of the M103 E26 engine

  • Most often, car owners with such a power unit are faced with lubricant leaks.
  • The weak points for leaks here are the U-shaped gasket and the crankshaft oil seal.
  • The second most common problem is engine failure due to clogged injectors.
  • The reason for the oil burner is usually in the valve stem seals and it goes away after they are replaced.
  • After 150,000 km, a single-row timing chain may already stretch and require replacement.

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