Mercedes-Benz Engine

OM646

The Mercedes-Benz OM646 is a I4 diesel piston engine.

Years
2003–2010
Configuration
I4
Fuel
Diesel
Top power
170 PS

Eighty changed components turned the OM611 into the engine that ran the whole 2000s range.

It arrived in 2002 in the W211 E 220 CDI as a reworking rather than a replacement, and the reworking was thorough. Bosch common rail at up to 1,600 bar, injectors spraying through seven holes, and — new here — a double pilot injection that warmed the chamber before the main event so the pressure rise was gentler and the clatter less. The variable-geometry turbo gained electronic vane control, the intake kept switchable swirl and tangential ports, the mechanical lift pump gave way to an electric one in the tank, and the 220 CDI versions ran a pair of Lanchester balance shafts.

From there it went nearly everywhere: C-Class, E-Class, CLK, CLC, Vito and Viano, the W906 Sprinter, and — as the OM644, turned sideways for front-wheel drive — the Chrysler PT Cruiser 2.2 CRD. The 2006 EVO revision altered ninety more parts, dropping compression to 17.5:1 on taller pistons and shorter rods, fitting ceramic glow plugs and giving every version balance shafts; it also absorbed the work of the five-cylinder OM647. Outputs ran from 88 to 170 PS before the OM651 took over in 2010.

Versions.

Every factory version of the OM646.

VersionDisplacementBore × StrokeCompressionPowerTorque
646.811 (DE 22 LA LR)2,148 cc 88 × 88.3 mm 17.5100 kW (134 hp; 136 PS) at 3,800 rpm270 N·m (199 lb·ft) at 1,600 rpm
646.811 (DE 22 LA)2,148 cc 88 × 88.3 mm 17.5125 kW (168 hp; 170 PS) at 3,800 rpm400 N·m (295 lb·ft) at 2,000 rpm
646.9512,148 cc 88 × 88.3 mm 18.090 kW (121 hp; 123 PS) at 4,200 rpm270 N·m (199 lb·ft) at 1,400 rpm
646.9522,148 cc 88 × 88.3 mm 17.5100 kW (134 hp; 136 PS) at 3,800 rpm340 N·m (251 lb·ft) at 1,800 rpm
646.9532,148 cc 88 × 88.3 mm 17.5125 kW (168 hp; 170 PS) at 3,800 rpm400 N·m (295 lb·ft) at 2,000 rpm
646.9612,148 cc 88 × 88.3 mm 18.0110 kW (148 hp; 150 PS) at 4,200 rpm340 N·m (251 lb·ft) at 2,000 rpm
646.9622,148 cc 88 × 88.3 mm 18.090 kW (121 hp; 122 PS) at 4,200 rpm270 N·m (199 lb·ft) at 1,600 rpm
646.9632,148 cc 88 × 88.3 mm 18.0110 kW (148 hp; 150 PS) at 4,200 rpm340 N·m (251 lb·ft) at 2,000 rpm
646.982 (DE 22 LA LR)2,148 cc 88 × 88.3 mm 18.080 kW (107 hp; 109 PS) at 3,800 rpm270 N·m (199 lb·ft) at 1,600 rpm
646.982 (DE 22 LA LR)2,148 cc 88 × 88.3 mm 18.080 kW (107 hp; 109 PS) at 3,800 rpm290 N·m (214 lb·ft) at 1,600 rpm
646.982 (DE 22 LA LR)2,148 cc 88 × 88.3 mm 18.085 kW (114 hp; 116 PS) at 3,800 rpm290 N·m (214 lb·ft) at 1,600 rpm
646.982 (DE 22 LA)2,148 cc 88 × 88.3 mm 18.0110 kW (148 hp; 150 PS) at 3,800 rpm330 N·m (243 lb·ft) at 1,800 rpm

Applications.

Every model powered by the OM646.

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