Mercedes-Benz M103 engine


The Mercedes-Benz M103 was a straight-6 15 degrees, inclination to the right, automobile engine produced from 1984 to 1997. It was a single overhead cam design with 2 valves per cylinder. The M103 was replaced by the M104 starting in 1989. The bore spacing on the M103 engine is 97mm.

3.0 L

The 103.980 engine produces at 5700 rpm with catalyst, at 5700 rpm without catalyst, and has a torque of at 4400 rpm, at 4400 rpm without catalyst. It uses the CIS-E and has a bore and a stroke of. The compression ratio is 9.2:1 with a redline of 6200 rpm. The firing order is 1-5-3-6-2-4. Lubrication system is pressure circulation lubrication system. Amount of oil in engine is and amount of coolant is. Number of valves is 1 intake, 1 exhaust with V-shaped overhead configuration. Valve operation was 1 top camshaft. Camshaft drive was simple roller-type chain. Starter motor is electrical with ; since 01.88 was. Ignition system is electronic ignition system. Recommended fuel octane for the M103 is 91 RON/MON. This engine can be found in the W124 E-Class, W126 S-Class, Mercedes-Benz R129, W463 G-Class and the R107.

2.6 L

The smaller 103.940 engine produces at 5800 rpm with catalyst, at 5800 rpm without catalyst, and generates torque at at 4600 rpm with catalyst, at 4600 rpm without catalyst. It also used the CIS-E engine management system and had a bore and a stroke of. The only mechanical differences from the M103 3.0 L to the M103 2.6 L were the decrease in bore, smaller intake valves and a slightly different airbox. The CIS-E components between 2.6 and 3.0 variants are all shared for any given model year with the exception of the ECU making engine swaps from 2.6 to 3.0 virtually bolt-in. This engine can be found in the W201, W124 E-Class and W126 S-Class.