Engine Lubrication And Oil Circuit - Mercedes-Benz OM 651 Service Manual

Engine lubrication and oil circuit

Lubricating system
The engine lubrication system minimizes the mechan-
ical friction and thus the wear on moving parts. In
addition, the oil pads between the bearings and
running surfaces reduce shocks and vibrations. A
pressure differential valve is installed in parallel to the
oil-water heat exchanger to ensure that the engine is
lubricated at all times. This allows the oil to be routed
around the oil-water heat exchanger.
Oil circuit
All of the moving components of the engine are lubri-
cated and / or cooled with engine oil via the oil circuit
of the engine.
The oil circuit of the engine is supplied with engine oil
via the oil pump. In addition, the vacuum pump is
driven and supplied with engine oil via the oil pump.
The following components in the crankcase are
supplied with engine oil via the main oil duct:
• Crankshaft bearings
• Connecting rod bearings
• Intermediate gears
• Oil spray nozzles
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Introduction of New Generation of 4-Cylinder Inline Engines, OM 651
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– This printout will not be recorded by the update service. Status: 09 / 2008 –
The two turbochargers are supplied with engine oil via
a bypass of the main oil duct.
The oil supply for the cylinder head branches off from
the main oil duct. The following lubrication points in
the cylinder head are supplied with engine oil:
• Cam chain tensioner
• Intake camshaft
• Exhaust camshaft
• Hydraulic valve clearance compensator
The engine oil is returned to the oil pan via return
ducts.
Oil pump
i Note
The CDI control unit reads in the oil level check
switch to monitor the oil level and the oil temper-
ature sensor to monitor the oil temperature.