Lubrication Description
Engine lubrication is supplied by a variable displacement two-stage vane-type oil pump assembly. An oil control solenoid valve, controlled by the engine control module (ECM) and mounted to the oil pump, will vary engine oil pressure according to engine needs based on speed and load. Oil pressure may change quickly as the engine speed or load varies. Oil pressure may also vary with outside temperature and oil viscosity. This is considered normal. The oil pump is mounted to the engine block oil pan rail and main bearing caps and is driven by a dedicated timing chain. The pump rotor and vanes rotate and draw oil from the oil pan sump through a pick-up screen and pipe. The oil is pressurized as it passes through the pump and is sent to the oil cooler if equipped for oil conditioning.
Pressurized oil is directed through the oil pan to the full flow oil filter (7) where harmful contaminants are removed. A bypass valve is incorporated into the oil filter, which permits oil flow in the event the filter becomes restricted. Oil exits the oil filter and is then directed to the main oil gallery. Oil from the main oil gallery is directed to the crankshaft bearings (5), piston oil nozzle (4) used for piston cooling under certain conditions, and the cylinder heads via drilled passages.
Oil that has entered the cylinder heads is used to actuate the camshaft position phasors (1), pressurize the hydraulic lash adjusters (3), lubricate the cam bearings (2) and valve train, and actuate cylinder deactivation and reactivation though ECM control of the active fuel management (AFM) oil control valves located on the camshaft covers. With active fuel management activated, the ECM commands the two AFM solenoids to open, directing oil through the camshaft cover and cylinder head oil galleries to deactivate the intake and exhaust valve for cylinders 2 and 5.
Oil returning to the pan is directed by the crankshaft oil deflector. The oil pressure sensor is located at the left front of the engine.