Lubrication Description
The lubrication system is based on pressure lubrication. The lubricant is carried along in the oil pan and distributed to the consumers by oil pressure. The oil return into the oil pan is guaranteed by gravitational force partwise through return pipes/channels.
The oil pump (9) sucks oil from the oil pan through the oil suction pipe. The pump is driven over a gear set by the balance shaft, which is powered by the crankshaft over a chain system.
The oil is pumped under pressure through the oil cooler (10) into the oil filter (11), where contaminants are removed. An engine fixed oil filter bypass valve inside the filter thread guarantees oil flow if the filter may be blocked by dirt or at very cold engine starts.
After the oil filter the oil is distributed into three different directions. Through one channel (7) the balance shaft bearings (12) are supplied with oil and the oil pump gets a pressure feedback to control the oil pump.
The correct operation of the chain drive for the balance shaft is provided with a chain tensioner (8) which is fed over the second channel.
The third channel enters the main oil gallery (6) where the oil is distributed to the crankshaft bearings (15) and the piston cooling jets (13). A groove around each upper main bearing furnishes oil to the drilled crankshaft passages from where it is provided to the connection rods (14).
The oil pressure needs to be controlled to guarantee the right oil pressure depending on engine load, speed and temperature. Therefore an oil pressure sensor (17) is mounted to the cylinder head gasket restrictor orifice. The sensor supply their signals to the engine control module (ECM).
Another part of this pressure regulation is the oil control valve (OCV) that is mounted to the oil pump. The OCV is a solenoid valve, which is fed by an oil channel that comes back from the balance shaft bearings. By means of the ECM signal the OCV is able to control the oil flow of the continuous variable oil pump and thus the oil pressure in the main gallery.
After passing the main gallery a part of the oil flows through the turbocharger oil feed pipe (5) to provide the turbocharger bearing (4) with oil.
Further the chain tensioner (16) for the timing chain is pressurized over the main oil gallery.
The variable camshaft phasers (1) are also supplied with the full oil pressure from the main oil gallery through the first cam shaft bearings, where as the other camshaft bearings (2), hydraulic lash adjusters (19) and the high pressure fuel pump (3) are fed with a lowered oil pressure through the cylinder head gasket restrictor orifice (18).