The Mercedes M102 engine is an inline 4-cylinder gasoline engine from Mercedes-Benz for passenger cars W123, W124, W201 and SUV W460/461. The engine appeared in 1980 to replace the M115 series motors and was produced in different volumes and configurations until 1996.
R4 Mercedes engines: M102, M111, M166, M254, M260, M264, M266, M270, M271, M274, M282.
The 102 series of Mercedes engines has been developed from the ground up. Along with the 2.0-liter versions, it includes 1.8 and 2.3-liter engines, as well as sports 2.5-liter ones. The cast iron cylinder block was rebuilt, two types of crankshafts were installed. The cylinder head for 8 valves and with one camshaft did not receive hydraulic valve clearances.
The single-row timing chain drive earned fame as an unreliable and quickly out of service part, and in 1987 it was replaced by a double-row chain. The average service life of the timing drive in the M102 E20 motor is 150 thousand kilometers. In 1984, as a result of modernization, the engine received lightweight connecting rods and a crankshaft, as well as hydraulic lifters, other engine mounts and an oil filter.
Specifications
| Production years | 1980-1993 |
| Displacement, cc | 1797 (M 102 E 18) 1996 / 1997 (M 102 E 20) 2298 / 2299 (M 102 E 23) |
| Fuel system | KE-Jetronic (M 102 E 18) carburetor / Jetronic (M 102 E 20) carburetor / Jetronic (M 102 E 23) |
| Power output, hp | 109 (M 102 E 18) 86 – 122 (M 102 E 20) 95 – 136 (M 102 E 23) |
| Torque output, Nm | 150 (M 102 E 18) 165 – 178 (M 102 E 20) 170 – 205 (M 102 E 23) |
| Cylinder block | cast iron R4 |
| Block head | aluminum 8v |
| Cylinder bore, mm | 89 (M 102 E 18) 89 (M 102 E 20) 95.5 (M 102 E 23) |
| Piston stroke, mm | 72.2 (M 102 E 18) 80.2 / 80.25 (M 102 E 20) 80.2 / 80.25 (M 102 E 23) |
| Compression ratio | 9.0 (M 102 E 18) 8.0 – 9.0 (M 102 E 20) 8.0 – 9.0 (M 102 E 23) |
| Features | no |
| Hydraulic lifters | yes (M 102 E 18) after 1984 (M 102 E 20) after 1984 (M 102 E 23) |
| Timing drive | chain |
| Phase regulator | no |
| Turbocharging | no |
| Recommended engine oil | 5W-40 |
| Engine oil capacity, liter | 5.0 (M 102 E 18) 4.5 / 5.0 (M 102 E 20) 4.5 / 5.0 (M 102 E 23) |
| Fuel type | petrol |
| Euro standards | EURO 0/1 |
| Fuel consumption, L/100 km (for Mercedes 190 2.0 E 1991) — city — highway — combined |
14.7 8.2 11.0 |
| Engine lifespan, km | ~400 000 |
| Weight, kg | 165 |
The engine was installed on:
- Mercedes C-Class W201 in 1982 – 1993;
- Mercedes E-Class W123 in 1980 – 1986; E-Class W124 in 1985 – 1992;
- Mercedes G-Class W460 in 1980 – 1989.
Disadvantages of the Mercedes M102 engine
- The most famous engine problem is camshaft wear at 150,000 km.
- In second place is the oil burner and its cause is most often in valve stem seals.
- Vibrations, knocks under the hood usually disappear with the replacement of the pillows of the power unit.
- The single-row timing chain runs very little, and the new double-row only a little longer.
- Until 1984, there were no hydraulic lifters and the valves were adjusted every 10,000 km.
8-valve carburetor versions
| Version | Model | Displacement | Piston stroke × Cylinder bore, mm | Power | Torque output | Production years |
| M102 V20 | 102.921 | 2,0 l. | 80,25 × 89 | 66 kW (90 hp) | 165 Nm | 1982–1984 |
| 102.938 | 63 kW (86 hp) | – | 1982–1984 | |||
| 102.924 | 77 kW (105 hp) | 170 Nm | 1984–1986 | |||
| 80 kW (109 hp) | 165 Nm | 1986–1988 | ||||
| 77 kW (105 hp) | 160 Nm | 1986–1988 | ||||
| 2,0 l. | 80,2 × 89 | 165 Nm | 1988–1989 | |||
| 75 kW (102 hp) | 160 Nm | 1988–1989 | ||||
| 75 kW (102 hp) | 158 Nm | 1989–1991 | ||||
| 102.920 | 2,0 l. | 80,25 × 89 | 80 kW (109 hp) | 170 Nm | 1980–1986 | |
| 102.939 | 74 kW (101 hp) | – | 1980–1985 | |||
| 102.922 | 80 kW (109 hp) | 170 Nm | 1985–1986 | |||
| 80 kW (109 hp) | 165 Nm | 1986–1989 | ||||
| 77 kW (105 hp) | 160 Nm | 1986–1990 | ||||
| 2,0 l. | 80,2 × 89 | 77 kW (105 hp) | 158 Nm | 1989–1990 | ||
| M102 V23 | 102.944 | 2,3 l. | 80,25 × 95,5 | 80 kW (109 hp) | 174 Nm | 1986–1989 |
| 102.942 /945 | 70 kW (95 hp) | 170 Nm | 1982–1989 | |||
| 102.946 | 77 kW (105 hp) | 182 Nm | 1989–1995 |
Injection 8-Valve Versions
| Version | Model | Displacement | Piston stroke × Cylinder bore, mm | Power | Torque output | Production years |
| M102 E18 | 102.910 | 1,8 l. | 72,2 × 89 | 80 kW (109 hp) | 150 Nm | 1990–1993 |
| M102 E20 | 102.962 | 2,0 l. | 80,25 × 89 | 90 kW (122 hp) | 178 Nm | 1982–1986 |
| 87 kW (118 hp) | 172 Nm | 1985–1988 | ||||
| 2,0 l. | 80,2 × 89 | 90 kW (122 hp) | 178 Nm | 1988–1991 | ||
| 87 kW (118 hp) | 172 Nm | 1988–1991 | ||||
| 90 kW (122 hp) | 175 Nm | 1991–1993 | ||||
| 102.963 | 2,0 l. | 80,25 × 89 | 90 kW (122 hp) | 178 Nm | 1985–1989 | |
| 87 kW (118 hp) | 172 Nm | 1985–1989 | ||||
| 2,0 l. | 80,2 × 89 | 87 kW (118 hp) | 172 Nm | 1989–1992 | ||
| 102.964 | 2,0 l. | 80,25 × 89 | 90 kW (122 hp) | 178 Nm | 1986–1991 | |
| 87 kW (118 hp) | 172 Nm | 1986–1991 | ||||
| 102.965 | 2,0 l. | 80,2 × 89 | 87 kW (118 hp) | 172 Nm | 1990–1994 | |
| M102 E23 | 102.961 | 2,3 l. | 80,25 × 95,5 | 83 kW (113 hp) | – | 1983–1984 |
| 102.985 | 2,3 l. | 80,2 × 95,5 | 87 kW (122 hp) | – | 1984–1986 | |
| 100 kW (136 hp) | 205 Nm | 1986–1991 | ||||
| 97 kW (132 hp) | 198 Nm | 1986–1991 | ||||
| 100 kW (136 hp) | 200 Nm | 1991–1993 | ||||
| 102.980 | 2,3 l. | 80,25 × 95,5 | 100 kW (136 hp) | 205 Nm | 1980–1986 | |
| 102.982 | 97 kW (132 hp) | 198 Nm | 1985–1989 | |||
| 2,3 l. | 80,2 × 95,5 | 97 kW (132 hp) | 198 Nm | 1989–1992 | ||
| 102.981 | 2,3 l. | 80,25 × 95,5 | 92 kW (125 hp) | 192 Nm | 1982–1985 | |
| 102.987 | 2,3 l. | 80,2 × 95,5 | 92 kW (125 hp) | 192 Nm | 1986–1991 | |
| 90 kW (122 hp) | 188 Nm | 1986–1991 | ||||
| 102.979 | 90 kW (122 hp) | 188 Nm | 1992–1996 | |||
| 102.989 | 93 kW (126 hp) | 190 Nm | 1990–1994 |
Injection 16 Valve Versions
| Version | Model | Displacement | Piston stroke × Cylinder bore, mm | Power | Torque output | Production years |
| M102 E23/2 | 102.983 | 2,3 l. | 80,25 × 95,5 | 136 kW (185 hp) | 235 Nm | 1983–1987 |
| 130 kW (177 hp) | 230 Nm | 1985–1988 | ||||
| 125 kW (170 hp) | 220 Nm | 1985–1988 | ||||
| M102 E25/2 | 102.990 | 2,5 l. | 87,2 × 95,5 | 150 kW (204 hp) | 240 Nm | 1988–1993 |
| 143 kW (195 hp) | 235 Nm | 1988–1993 | ||||
| 102.991 | 2,5 l. | 82,8 × 97,3 | 150 kW (204 hp) | 240 Nm | 1989 | |
| 143 kW (195 hp) | 235 Nm | 1989 | ||||
| 102.992 | 173 kW (235 hp) | 245 Nm | 1990 |
