Engine Mercedes M102

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.

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.

1st gen Mercedes R4 family: M102, M111 E18, M111 E20, M111 E22, M111 E23, M166, M266, M271 E16, M271 E18.

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

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

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.

Frequently asked questions about the Mercedes M102