|This article relies largely or entirely upon a single source. (February 2009)|
|Displacement||2,987 cc (182.3 cu in)|
|Cylinder bore||83 mm (3.3 in)|
|Piston stroke||92 mm (3.6 in)|
|Cylinder block alloy||Aluminum|
|Cylinder head alloy||Aluminum|
|Fuel system||Common rail injection|
european models: 195 kW (265 PS; 261 hp). US vehicles: 157 kW (213 PS; 211 hp).Mercedes/Dodge Sprinter: 140 kW (190 PS; 190 hp).
european models: 620 N·m (460 lb·ft). , US vehicles: 540 N·m (400 lb·ft).Mercedes/Dodge Sprinter: 440 N·m (320 lb·ft).
|Dry weight||208 kg (459 lb)|
The Mercedes-Benz OM642 engine is a 3.0-liter, 72° 24-valve, aluminum block diesel V6 engine manufactured by the Mercedes-Benz division of Daimler AG as a replacement for the Mercedes-Benz inline-5 and -6 engines.
The engine features common rail fuel injection and a variable nozzle turbocharger. The injection system operates at 1,600 bar (23,000 psi), while the compression ratio is 18:1. The engine features a counter-rotating balance shaft mounted between the cylinder banks to cancel the vibrations inherent to the 72 degree V6 design, and the crankpins are offset by 48 degrees to achieve even 120 degree firing intervals. In some heavy vehicle applications, Mercedes' BlueTec AdBlue urea injection is utilised for NOx reduction. In lighter vehicle applications, a NOx storage catalyst captures nitrous oxides, which are periodically purged (decomposed) by running the engine slightly rich. A particulate filter lowers soot, making this engine ULEV certified. Engine mass is 208 kg (459 lb). Power output is 165 kW (224 PS; 221 hp) and 510 N·m (380 lb·ft) of torque. For the 2007 model year, torqe is raised to 540 Nm. For the 2012 model year, output on US mercedes diesel vehicles will be raised to 240 horsepower and 455 lb-ft of torque.
The engine is manufactured at the Daimler AG plant in Marienfelde, Berlin, Germany. Due to the inordinate number of pre-2010 OM642 engines needing repair due to heat-related seal degradation causing oil cooler leaks, Mercedes reformulated the seals from an orange color rubber to a purple color Viton seal now used in all 2010 and later engines. There is a Mercedes Technical Service Bulletin that states that the leak can be attributed to an improperly installed seal. Oil specification MB 229.51 or MB 228.31 is recommended/
In addition to the oil cooler seals; this engine can also have an issue with the design of the positive crankcase ventilation system. The crankcase ventilation system vents to the inlet of the turbo. The issue is that the air vented from the crankcase contains too much oil to easily pass through the swirl motor valves downstream of the turbo. Once this oil and sludge begin to accumulate, the valve becomes inoperative and blows a fuse that controls many other sensors required to properly operate the engine and emission system. This will immediately place the vehicle into limp home mode and limit the rpm to 3000. It also causes a check engine light and numerous OBDII Codes. Mercedes Benz has previously recognized this feature of the vehicle and has stated that this engine feature; the accumulation of oil at the turbo inlet; is "normal". In a Technical Service Bulletin they issued in 2008 they state: "Engine oil venting occurs on the right hand side of the engine air intake duct. For this reason there is always some oil in the engine air intake duct, see (Figure 3). This is no justification for replacing the turbocharger. Turbochargers replaced for this reason will not be covered by warranty." While a slight amount of oil may be normal and acceptable, sufficient quantities and accumulation will indeed lead to other failures as identified above.
Vehicles using this engine include:
- Dodge / Freightliner Trucks / Mercedes-Benz Sprinter (2006–Present)
- Jeep Grand Cherokee WK (20051-20072-2008)
- Mercedes-Benz C320 CDI (2007–Present)
- Mercedes-Benz E280 & E320 CDI/Bluetec (2007-2009)
- Mercedes-Benz C350 CDI (2009–2009)
- Mercedes-Benz E350 Bluetec (2010–Present)
- Mercedes-Benz R320/350 CDI/Bluetec (2007–Present)
- Mercedes-Benz ML320/350 CDI/Bluetec (2007–Present)
- Mercedes-Benz GL320/350 CDI/Bluetec (2007–Present)
- Mercedes-Benz S320/350 CDI/Bluetec (2005–Present)
- Chrysler 300 (2006-2011) (Europe and Australia only)
- Mercedes-Benz Vito Van 120 cdi and Vito 204 Sports (2006–Present UK)
- "05_kompact_en.doc". ourexcellentadventures.com. Retrieved 2009-02-13.
- Consumer Reports: What is BlueTec?
- Motive Magazine ULEV certification, Diesel Car Bomb BlueTec
- "Mercedes-Benz C 320 CDI". auto-innovations.com. Retrieved 2009-02-13.
- Mercedes Benz (January 2013). "Traces of oil in area of oil cooler (inner V) on engine 642". Technical Service Bulletin (LI18.30-P-055434).
- Mercedes Benz (June 2008). "Diesel Engine - Oil Leak at Engine Air Intake Duct". Technical Service Bulletin. Order No.: S-B-09.20/29.