Engine lubrication process (Nissan Murano Z50)

The engines are equipped with a pressure lubrication system. Oil is supplied by the oil pump through the oil receiver screen from the oil sump and passes under pressure through the oil filter into the main oil circuit.

The pressure relief valve, which is located at the outlet of the oil pump, opens when the oil pressure increases above 5.6 bar, and part of the oil goes back into the oil sump.

Oil enters the main channel through the central axis of the filter cartridge. There is an oil pressure switch sensor that indicates to the driver a drop in oil pressure by lighting a warning light on the dashboard. The warning light comes on when the oil pressure drops below 0.3 bar. A bypass valve allows unfiltered oil to pass into the main channel.

The main channel is connected to the lubrication channels for the crankshaft bearings. Oil flows to the connecting rod bearings through inclined holes, and at the same time it rises along an inclined channel into the cylinder head, lubricating the camshaft bearings, tappets, and valve stems there.

At the front of the engine, oil from the main oil gallery lubricates the camshaft drive chain through an injector.

The oil pump is installed in the front engine cover. The inner rotor of the oil pump is connected to the crankshaft.

The system also includes an oil cooler. Some of the oil after the oil pump goes to the oil radiator, which serves to improve cooling of the oil and the engine.

Figure HM.04.001 shows the left cylinder head and the left row of the cylinder block. The oil circulation diagram in the right head and the right row of the cylinder block is similar, but it should be kept in mind that the oil pump, oil intake, oil filter and oil radiator are one for the entire engine.

Engine oil circulation diagram