Oil pump (240) sucks engine oil from the oil pan and pumps it into the main circuit oil filter (275). Between the discharge and suction area of the oil pump is an oil pressure relief valve (from about 5 bar). Due to this, part of the oil is poured into the suction space. The oil level sensor is located on the side of the oil pan (351).
The engine oil is forced, bypassing the recirculation shut-off valve, into the oil filter. The recirculation shut-off valve prevents oil from entering the oil pan when the engine is stopped.
From the oil filter, the purified oil enters the main oil channel. When the oil filter is clogged, the bypass valve directs untreated oil directly into the main oil passage.
From the main oil channel there are branches for lubricating the crankshaft bearings. Through inclined holes in the crankshaft, oil enters the connecting rod bearings, and inside the connecting rod body, to the piston pins. Through oil injection nozzles (238) cooling oil is injected onto the base of the pistons.
At the same time, engine oil enters the cylinder head through the injection pipes and there it provides lubrication of the chain tensioner, camshaft bearings (185) and poppet pushers (203). The fuel pump is additionally lubricated through the transverse holes (1) and fuel advance clutch (18) and, if present, a turbocharger.
- A - crude oil to the air-to-oil cooler
- B - crude oil from the air-to-oil cooler
Attention! The 2.2/2.5L engines have an oil-to-coolant heat exchanger located next to the oil pan instead of the air-to-oil cooler.