Engine Lubrication: Description and Operation

LUBRICATION SYSTEM - Description

A pressure feeding lubrication system has been adopted to supply oil to the moving parts of this engine. The lubrication system consists of an oil pan, oil pump and oil filter, etc. The oil circuit is shown in the image. Oil from the oil pan is pumped up by the oil pump. After it passes through the oil filter, it is fed through the various oil holes in the crankshaft and cylinder block. After passing through each part of the cylinder block and performing its lubricating function, the oil is returned by gravity to the oil pan. A dip stick below the cylinder block is provided to check the oil level.

OIL PUMP
The oil pump pumps up oil from the oil pan and sends it under pressure to the various parts of the engine. An oil strainer is mounted in front of the inlet to the oil pump to remove impurities. The oil pump is a trochoid type pump, which uses a drive rotor and driven rotor inside the pump body. When the drive rotor rotates, the driven rotor rotates in the same direction. The axis of the drive rotor shaft is different from the center of the driven rotor, so when both rotors rotate, the space between the two rotors changes. Oil is drawn in when this space widens, and is discharged when the space becomes narrow.

OIL FILTER
The oil filter is a full flow type filter with a relief valve built in the paper filter element. Particles of metal from wear, airborne dirt, carbon and other impurities can get in the oil during use and could cause accelerated wear or seizing if allowed to circulate through the engine. The oil filter, integrated into the oil line, removes these impurities as the oil passes through it. The filter is mounted outside the engine to simplify replacement of the filter element. A relief valve is also included ahead of the filter element to relieve the high oil pressure which occurs if the filter element becomes clogged with impurities. The relief valve opens when the oil pressure overpowers the force of the spring. Oil passing through the relief valve bypasses the oil filter and flows directly into the main oil hole in the engine. A relief valve is also built in the oil filter bracket.

ENGINE OIL AUTO FEEDER SYSTEM
When the ECM detects that the oil level in the oil pan is low, it automatically supplies oil to the engine from the oil tank.
During engine starting, if the ECM judges from the signal from the engine oil level sensor that the engine oil level in the oil pan is low, it operates the motor installed on the oil tank so that a specified volume of oil is supplied from the oil tank to the engine to reach the required level.
If for some reason the oil level falls below the specified level, the oil level warning light remains on. If the system is faulty, the oil level warning light in the combination meter blinks to inform the driver. At the same time, the malfunction details are recorded as a diagnostic trouble code by the ECM. The diagnostic trouble code is accessed by looking at the engine oil level warning light blinking in a specific pattern for each malfunction. There are four different types of diagnostic trouble code, including the normal code.