Engine Lubrication Flow
| Callout | Component Name |
|---|---|
| 1 | Upper Main Oil Galleries |
| 2 | Valve Lifters |
| 3 | Oil Pressure Sensor |
| 4 | Oil Pressure Relief Valve |
| 5 | Bypass Valve- Oil Cooler |
| 6 | Oil Filter |
| 7 | Engine Oil Cooler |
| 8 | Oil Pan Sump |
| 9 | Oil Pump Screen |
| 10 | Pressure Relief Valve- Oil Pump |
| 11 | Oil Pump |
| 12 | Crankshaft Bearings |
| 13 | Camshaft Bearings |
Engine lubrication is supplied by a gerotor type oil pump assembly (11). The pump is mounted on the front of the engine block and driven directly by the crankshaft sprocket. The pump gears rotate and draw oil from the oil pan sump (8) through a pick-up screen and pipe (9). The oil is pressurized as it passes through the pump and is sent through the engine block lower oil gallery. Contained within the oil pump assembly is a pressure relief valve (10) that maintains oil pressure within a specified range.
Pressurized oil is directed through the engine block lower oil gallery to the full flow oil filter (6) where harmful contaminants are removed. Oil exits the oil filter and is then directed to the external oil cooler (7). A bypass valve (5) is incorporated into the oil cooler assembly in the event oil flow within the cooler is restricted. A second valve, the active fuel management oil pressure relief valve (4) is incorporated into the oil pan. The active fuel management oil pressure relief valve limits oil pressure to 379-517 kPa (55-75 psi) maximum.
Oil returns from the oil cooler and is directed to the upper main oil galleries (1). Oil from the left upper oil gallery is directed to the crankshaft bearings (12) and camshaft bearings (13). Oil that has entered both the upper main oil galleries also pressurizes the valve lifter assemblies (2) and is then pumped through the pushrods to lubricate the valve rocker arms and valve stems. Oil returning to the pan is directed by the crankshaft oil deflector. The oil pressure sensor (3) is located at the top rear of the engine.