The gerotor oil pump, driven by the engine crankshaft, draws unfiltered oil from the oil pan through an oil
pick-up tube into the inlet port of the front cover. Unfiltered oil (under pressure) flows through the outlet port in the front cover into the unfiltered oil gallery in the crankcase.
The unfiltered oil gallery has one exit port to the header of the oil cooler. The oil is then internally diverted to the oil cooler plate stack or by-passed into the oil cooler/filter module.
An oil temperature control valve, in the oil cooler/filter header, senses inlet oil temperature. During engine start-up, when the oil is cold, the oil temperature control valve allows unfiltered oil to bypass the oil cooler plate stack. When the unfiltered oil reaches engine operating temperature, the oil temperature control valve routes unfiltered oil to the oil cooler. Oil flows through both the oil cooler core and bypass gallery when the valve is partially open.
Unfiltered oil at full flow moves through plates in the oil cooler. Engine coolant flows through the plates to cool the surrounding oil.
The cooled, unfiltered oil leaving the oil cooler stack mixes with the uncooled, unfiltered oil (that bypassed the oil cooler). The oil mixture flows through the oil filter (from element outside to element inside). The oil filter bypass valve in the header ensures full flow of oil to the engine should the filter element become plugged. Oil bypass occurs within the module when differential filter pressure reaches 345 kPa (50 psi).
Cooled, filtered oil flows to and past the oil pressure regulator relief valve, in the oil cooler module. The oil pressure regulator valve maintains correct operating oil pressure.
The pressure regulator valve opens at 379 kPa (55 psi) and dumps excess oil into the crankcase.
The filtered oil continues to the main oil gallery for distribution throughout the engine.
Connecting rod bearings are fed through drilled passages in the crankshaft from main journals to rod journals, that receive pressurized oil from the main bearings.
Camshaft journals are fed through passages drilled vertically in the main bearing webs. Pressurized oil from the main gallery, through piston cooling tubes, lubricates and cools the pistons.
Valve rocker arms are lubricated through an annulus on the outside of the rear camshaft bushing. The oil passes up and through the vertical gallery in the rear of the crankcase, through a passage in the cylinder head. Oil continues through rocker arm shaft pedestal and into the rocker arm shaft. Oil continues flowing through drillings in the rocker arm shaft to the rocker arms. The oil then drains to the oil pan sump through push rod holes.
Filtered oil from the main gallery flows up through a passage in the front of the crankcase and front cover into the oil reservoir for the high-pressure oil pump.
The turbocharger receives filtered oil through an external tube connected to the oil cooler header.
Oil drains back to the oil pan sump through a tube connected to the crankcase.
The air compressor (if equipped) receives filtered oil from the main oil gallery through an external tube
connected to the left side of the crankcase. Oil drains to the front cover and back to the oil pan.
The front gear train is splash lubricated with oil draining from the high-pressure reservoir and the air compressor (if equipped).
