The oil pump draws oil from the engine sump and delivers it to the oil filter. There is a bypass valve on the pressure side of the oil pump. If the oil pressure is too high, the valve opens and some of the oil flows back into the engine sump.
Through the middle of the oil filter element, clean oil enters the main oil line. When the filter becomes clogged, a bypass valve located in the oil filter housing supplies unfiltered oil directly to the main oil line. There is a non-return valve in the oil filter pipe, which prevents the oil passages and hydraulic valve lifters of the engine from emptying. Channels for lubricating the crankshaft bearings depart from the main oil line. Through inclined holes in the crankshaft, oil is supplied to the connecting rod bearings, and from there it is sprayed onto the piston pins and cylinders. At the same time, oil is supplied through ascending channels to the cylinder head and ensures lubrication of the camshaft bearings and the operation of hydraulic tappets.
Attention! On vehicles equipped with engines with a catalytic converter, it is necessary to ensure that the oil level on the dipstick is not above the maximum mark. If too much oil has been poured into a car with a catalytic converter, the excess must be removed from the crankcase by draining or suction (special vacuum pump), otherwise unburnt oil will enter the exhaust system and may destroy the catalytic converter.
Filling volume of the engine lubrication system 1MZ-FE:
- dry system filling - 5.5 l;
- with oil filter - 4 l;
- without oil filter - 4 l.
Pic. 2.192. Engine lubrication system 1MZ-FE and a schematic diagram of the system: 1 - oil pump; 2 - oil filter of the pump; 3 - oil filter
Oil pump
The oil pump with trochoidal gears is driven by a chain from the crankshaft. Through the pump, the oil receiver takes oil from the engine sump and supplies it under pressure to various friction units. An oil receiver with a strainer is located in front of the oil pump inlet pipe.
Oil pressure regulator (pressure reducing valve)
Oil pressure regulator (pressure reducing valve) performs the function of preventing excess oil supply. At low speeds, the regulator valve closes the bypass valve under the action of a spring (bypass) channel. Whereas at high speeds, oil pressure increases, the oil pressure force overcomes the spring force and the regulator valve opens. Excess oil is returned to the sump through the valve.
Oil filter
Camry vehicles use a full-flow type oil filter with a replaceable paper filter element. The filter is installed on the outside of the engine, which allows relatively quick replacement of the filter element. A bypass valve is installed in front of the filter element, which opens with an increase in pressure in front of the filter, which occurs if the filter element is clogged with contaminants. The bypass valve opens when the oil pressure exceeds the force of the valve spring. In this case, the oil passes through the bypass channel, bypassing the oil filter, and goes directly to the main engine oil line.