Mercedes-Benz M103 engine
The Mercedes-Benz M103 was a straight-6 15 degrees, crossflow cylinder head with an 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 97 mm. 3.0 L. The 103.980 engine of uses the CIS-E (Continuous Injection System - Electronic). This engine can be found in the W124 E-Class, W126 S-Class, Mercedes-Benz R129, W463 G-Class, R107 and Isdera Spyder 036i 3.0  12V. 2.6 L. The smaller 103.940 engine of also used the CIS-E engine management system. The only mechanical differences from the M103 3.0 L to the M103 2.6 L were the smaller bore and intake valves, with 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 (190), W124 E-Class and W126 S-Class.