The in-line 6-cylinder Mercedes M103 E30 engine was introduced in 1985 and was intended to replace the outdated M110 engine and was partially unified with the 4-cylinder M102.
The 103 series received a new lightweight cast iron cylinder block and a 12-valve block head with a single camshaft and hydraulic lifters, instead of the previous 24-valve twin-shaft, which was caused by a desire to increase efficiency, reduce the weight of the power plant and reduce the cost of its production. The diameter of the intake valves is 43 mm, exhaust 39 mm. Fuel injection system – mechanical injection. The timing drive uses a not very reliable single-row chain. 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 | 2960 |
| Fuel system | KE-Jetronic |
| Power output, hp | 180 – 190 |
| Torque output, Nm | 255 – 260 |
| Cylinder block | cast iron R6 |
| Block head | aluminum 12v |
| Cylinder bore, mm | 88.5 |
| Piston stroke, mm | 80.2 |
| Compression ratio | 9.2 – 10.0 |
| 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 300 SL R107) — city — highway — combined |
16.0 10.5 14.5 |
| Engine lifespan, km | ~450 000 |
The engine was installed on:
- Mercedes E-Class W124 in 1985 – 1993;
- Mercedes S-Class W126 in 1985 – 1991;
- Mercedes SL-Class R107 in 1985 – 1989, SL-Class R129 in 1989 – 1993;
- Mercedes G-Class W463 in 1990 – 1993.
Disadvantages of the M103 E30 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 E30
How much power does the Mercedes M103 E30 make?
The Mercedes M103 E30 develops 180 - 190 hp and 255 - 260 Nm of torque.
How much oil does the Mercedes M103 E30 take and which one?
Engine oil capacity: 6.0 liters. Recommended oil: 5W-40.
Does the Mercedes M103 E30 have a timing belt or chain?
The Mercedes M103 E30 uses a timing chain.
Is the Mercedes M103 E30 turbocharged?
No, the Mercedes M103 E30 is naturally aspirated.
Does the Mercedes M103 E30 need valve clearance adjustment?
No, the Mercedes M103 E30 has hydraulic lifters, so the valve clearances do not need to be adjusted.
How long does the Mercedes M103 E30 last?
The typical lifespan of the Mercedes M103 E30 is ~450 000 km with proper maintenance.
What is the fuel consumption of the Mercedes M103 E30?
300 SL R107: city 16.0, highway 10.5, combined 14.5 L/100 km.
What cars was the Mercedes M103 E30 installed on?
Mercedes E-Class W124 in 1985 - 1993; Mercedes S-Class W126 in 1985 - 1991; Mercedes SL-Class R107 in 1985 - 1989, SL-Class R129 in 1989 - 1993; Mercedes G-Class W463 in 1990 - 1993.
What are the common problems of the Mercedes M103 E30?
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.
