Mercedes-Benz OM 639 / OM 640 diesel engine

Technology

The OM 640 has one common-rail injection and four valves per cylinder. All variants are equipped with engine charging and intercooling. As usual with Mercedes, the overhead camshafts are driven by two timing chains .

The motor is inclined forwards by approx. 60 ° and is installed transversely behind the driven front axle on vehicles with sandwich floor . Power is transmitted via a manual gearbox with five (160 CDI) or six gears (180 CDI and 200 CDI) or via the continuously variable Autotronic . The engine and transmission could only be used in these vehicles due to their unusual installation position.

OM 640

Engine	designation	capacity	Bore · stroke	Compression ratio	power	torque	model
OM 640 DE 20 LA red.	640942	1991 cm³	83 x 92 mm	18: 1	60 kW (82 hp) at 4200 rpm	180 Nm at 1400-2600 / min	A 160 CDI
OM 640 DE 20 LA red.	640940	1991 cm³	83 x 92 mm	18: 1	80 kW (109 hp) at 4200 rpm	250 Nm at 1600-2600 / min	A 180 CDI, B 180 CDI
OM 640 DE 20 LA	640941	1991 cm³	83 x 92 mm	18: 1	103 kW (140 hp) at 4200 rpm	300 Nm at 1600-3000 / min	A 200 CDI, B 200 CDI

OM 639

On the basis of the OM 640, a version capped by a cylinder was used in the 2004 Smart Forfour and Mitsubishi Colt . Also, the OM 639 has timing chains and a common-rail injection, with the exception of the missing fourth cylinder, data such as bore and stroke are identical. However, the installation position is typical for front-wheel drive: engine standing transversely in front of the front axle. It was offered in two performance levels:

Engine	capacity	Hole · Hub	compression ratio	power	torque	model
OM 639 DE 15 LA red.	1493 cm³	83 x 92 mm	18: 1	50 kW (68 hp) at 4000 rpm	160 Nm at 1600 rpm	forfour cdi
OM 639 DE 15 LA	1493 cm³	83 x 92 mm	18: 1	70 kW (95 hp) at 4000 rpm	210 Nm at 1800 rpm	forfour 1.5 cdi