The Mercedes M104 E28 engine was developed on the basis of the M104 E32 to replace the previous M103 E26. A new crankshaft was installed in the cylinder block of the 3.2-liter, with a piston stroke of 73.5 mm.
The R6-family includes: M103 E26, M103 E30, M104 E28, M104 E30, M104 E32, M256 E30.
The cylinder head is similar to the M104 E32 with a variable valve timing system at the inlet. Fuel injection system – distributed injection. Intake manifold with variable geometry. The timing system uses a reliable two-row chain.
Specifications
| Production years | 1992-1998 |
| Displacement, cc | 2799 |
| Fuel system | injector |
| Power output, hp | 193 – 197 |
| Torque output, Nm | 265 – 270 |
| Cylinder block | cast iron R6 |
| Block head | aluminum 24v |
| Cylinder bore, mm | 89.9 |
| Piston stroke, mm | 73.5 |
| Compression ratio | 9.2 – 10.0 |
| Features | no |
| Hydraulic lifters | yes |
| Timing drive | chain |
| Phase regulator | at the intake |
| Turbocharging | no |
| Recommended engine oil | 5W-40 |
| Engine oil capacity, liter | 7.0 |
| Fuel type | petrol |
| Euro standards | EURO 1/2 |
| Fuel consumption, L/100 km (for E280 W124) — city — highway — combined |
14.5 11.0 12.5 |
| Engine lifespan, km | ~500 000 |
| Weight, kg | 195 |
Disadvantages of the M104 E28 engine
- The main problem of power units of this series is numerous oil leaks.
- First of all, gaskets leak: U-shaped, cylinder head and oil filter heat exchanger.
- The viscous coupling of the fan often fails, which is very dangerous for the engine.
- This motor is very afraid of overheating, the cylinder head is bent almost immediately.
- You will get a lot of trouble under the hood wiring, as well as ignition coils.
