The lubrication system has the following components:
- Oil pan
- Oil pump
- Oil cooler
- Oil filter
- Turbocharger oil lines
- Oil passages for the cylinder block
Engine oil flow schematic|
(1) Rocker arm shaft
(2) Oil passage to adjustable idler gear
(3) Camshaft bearing journals
(4) Oil passage to the fixed idler stub shaft
(5) Oil passage to air compressor
(6) Oil passage to cluster idler gear
(7) Piston cooling jet
(8) Crankshaft main bearings
(9) Oil manifold
(10) Oil passage from filter
(11) Oil supply line
(12) Bypass valve to the turbocharger
(13) Oil return line
(14) Oil filter
(15) Bypass valve for the oil cooler
(16) Oil pump
(17) Oil pan
(18) Oil cooler
(19) Regulator for the oil pump
(20) Suction lines
When the engine is warm, oil is drawn from the oil pan (17) through the suction lines (20) to the oil pump (16). The oil pump pushes the hot oil through the oil cooler (18). The oil is then sent to the oil filter (14). Oil from the oil filter is sent to the oil manifold (9) in the cylinder block and to the oil supply line (11) for the turbocharger. Oil from the turbocharger goes back through the oil return line (13) to the oil pan.
When the engine is cold, oil is drawn from the oil pan (17) through the suction lines (20) to the oil pump (16). When the oil is cold, an oil pressure differential in the bypass valves causes the bypass valves to open. These bypass valves then provide immediate lubrication to all of the engine components when cold oil with high viscosity causes a restriction to oil flow through the oil cooler (18) and the oil filter (14). The oil pump then pushes the cold oil through the bypass valve (15) for the oil cooler and through the bypass valve (12) for the oil filter. The oil then goes to the oil manifold (9) in the cylinder block and to the supply line (11) for the turbocharger. Oil from the turbocharger goes back through the oil return line (13) to the oil pan.
When the oil is warm, an oil pressure differential in the bypass valves causes the bypass valves to close. This differential continues the normal flow of oil through the oil cooler and the oil filter.
The bypass valves will also open when there is a restriction in the oil cooler or the oil filter. This prevents a restricted oil filter or a restricted oil cooler from stopping the lubrication of the engine. The system pressure is limited by the regulator for the oil pump (19).
The oil from the oil manifold (9) is sent under pressure through drilled passages to the crankshaft main bearings (8). The oil flows through drilled holes in the crankshaft. This oil lubricates the connecting rod bearings. A small amount of oil is sent to the piston cooling jets (7). The piston cooling jets spray oil on the underside of the pistons.
Oil flows through passages in the timing gear housing and the accessory drive gear. This oil flows to the air compressor through the oil passage (5).
Oil passage (2) provides oil to the adjustable idler gear. Oil passage (4) provides oil to the fixed idler gear. Oil passage (6) provides oil to the cluster gear. The oil flows through a passage in the shafts of the gears.
There is a pressure control valve in the oil pump. This valve controls the pressure of the oil that flows from the oil pump.
Oil flows into the cylinder head via a hollow locating dowel in the top deck of the cylinder block. Oil travels to the camshaft bearing journals (3) and the three center rocker arm shaft supports through drilled passages in the cylinder head. The supports supply oil to each rocker shaft. Oil flows to the bushings of the fuel injector rocker arm through holes in the rocker arm shaft (1). This same oil lubricates the valve and the rollers. Oil flows through drilled passages in the rocker arms. This oil lubricates the roller, the valve bridge and the contact surfaces of the actuator of the unit injector. Splash oil lubrication is used to lubricate other components of the valve system.
Excess oil returns to the engine oil pan.