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 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.
Mercedes R6 family: M103 E26, M103 E30, M104 E28, M104 E30, M104 E32, M256 E30.
Specifications
| 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 |
12.4 8.2 10.2 |
| Engine lifespan, km | ~450 000 |
The engine was installed on:
- Mercedes S-Class W126 in 1985 – 1991 (260 SE);
- Mercedes 190 W201 in 1986 – 1993 (190 E 2.6);
- Mercedes E-Class W124 in 1986 – 1993 (260 E, 300 E 2.6).
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.
Frequently asked questions about the Mercedes M103 E26
How much power does the Mercedes M103 E26 make?
The Mercedes M103 E26 develops 160 - 165 hp and 220 - 230 Nm of torque.
How much oil does the Mercedes M103 E26 take and which one?
Engine oil capacity: 6.0 liters. Recommended oil: 5W-40.
Does the Mercedes M103 E26 have a timing belt or chain?
The Mercedes M103 E26 uses a timing chain.
Is the Mercedes M103 E26 turbocharged?
No, the Mercedes M103 E26 is naturally aspirated.
Does the Mercedes M103 E26 need valve clearance adjustment?
No, the Mercedes M103 E26 has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the Mercedes M103 E26 last?
The typical lifespan of the Mercedes M103 E26 is ~450 000 km with proper maintenance.
What is the fuel consumption of the Mercedes M103 E26?
190 E W201: city 12.4, highway 8.2, combined 10.2 L/100 km.
What cars was the Mercedes M103 E26 installed on?
Mercedes S-Class W126 in 1985 - 1991 (260 SE); Mercedes 190 W201 in 1986 - 1993 (190 E 2.6); Mercedes E-Class W124 in 1986 - 1993 (260 E, 300 E 2.6).
What are the common problems of the Mercedes M103 E26?
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. All known problems.
