After passing through the oil filter, the purified oil enters the main oil line. It is equipped with an oil pressure warning sensor, which, by turning on the warning light in the instrument cluster, signals low oil pressure. The oil filter has a bypass valve through which, if the filter is heavily contaminated, uncleaned oil flows directly into the oil line.
From the main line, oil is supplied under pressure through channels to lubricate the main bearings of the crankshaft and then through channels in the crankshaft to the connecting rod bearings. To cool the pistons, oil is sprayed through nozzles onto the lower part of the pistons.
Attention! Do not fill the engine oil above the "Max" mark on the indicator (dipstick), as unburned oil can get into the exhaust system and damage the catalytic converter.
The channels supply oil to the cylinder head to lubricate the camshaft bearings and to the hydraulic tappets.
The oil pump is mounted in the front cover and is driven by two flats on the shaft.
The tightness of the connection between the oil pump and the cylinder block is ensured by means of a silicone composite sealant paste.
(Information copied from the resource PEUGEOTBOOK.ru)
Figure 4.22. Front engine cover with oil pump: 1 - front cover with oil pump; 2 - oil seal; 3 - crankshaft; C - pressure reducing valve; R - oil pump drive chamfers
The seal between the outlet of the oil pump and the channel in the cylinder block is ensured by means of a square section seal 2 (figure 4.22).
The oil pressure reducing valve C is located in the front cover.
The presence of an oil pressure regulator in the channel for supplying oil to the camshaft bearings serves to limit the oil pressure in the upper part of the engine.
An oil drain valve is built into the cylinder head at the level of the upward oil supply channel, which provides some oil reserve at the top of the engine for the hydraulic tappets.
The oil pressure sensor is located on the exhaust side of the engine to the left of the engine identification plate.
The electric oil level sensor is located at the oil pan level on the intake manifold side of the cylinder block.
An oil filter with a paper filter element is mounted on the oil/coolant heat exchanger support.