Mercedes-Benz M111 engine  The M111 engine family is a straight-4 automobile engine from Mercedes-Benz, produced from 1992 to 2003. Debuted in the 1992 Mercedes-Benz E-Class (W124), this engine family is relatively oversquare and uses 4 valves per cylinder. All engines in the family use a cast iron engine block and aluminum alloy cylinder head. The M111.920 is a 16 valve engine. It produces of power at 5500 rpm and at 4200 rpm. Starting with 1996 it has a variant called the M111.921 which has a MAF (Mass Air Flow)-sensor instead of MAP-sensor on the first one, and using ECU instead of PMS. Applications:  The M111.940 is a 16-valve engine with bore and stroke of and compression ratio of 9.6:1. It produces of power and of torque. Applications:  Unlike the 102, 103, and early 104 series engines, the engine did not use mechanical fuel injection but the Siemens PEC/PMS (Pressure Engine Control) management system, which integrates fuel and spark management. It is a speed-density type of system, as mixture formation is dependent on RPM, TPS angle, and manifold pressure (MAP). Injectors work in pairs (idle, part load), or altogether (full-load). It uses 2 ignition coils and no ignition distributor. Cylinders are fired in pairs (dual fire) - 1 and 4 together, and 2 and 3 together. The crankshaft position sensor is sensing the movement of two radially opposed position plates on the flywheel, one of which is magnetized, and the other is not. Thus, the engine management has precise information which group of cylinders to fire, and which group of injectors to spray. Similar to the M111.940 engine, used in the following years. It produces of power and of torque. Applications:  This motor never had PMS. Early models -95 to -97 has a HFM-motronic, hot-film type air/fuel metering device, and -97 to -2002 with ME2.1 motronic. The later system also has a magnet on the intake camshaft, and gives signal to ECU, to assist the motor in producing more torque at low revs. The early motor didn't have any camshaft position sensor, so wiring was much different. The only problem experienced with this M111 excellent reliability motor is the originally installed Victor Reinz headgasket, which eventually tore apart by age, and made the top lose coolant on the side.