Page 183 of 796
02-24
2) Oil Separator
Oil separator separates the particle in blow-by gas to minimize the engine oil consumption and reduces
the inflow oil from intake system into the combustion chamber. The separated oil returns to oil pan
through cylinder head.
Oil separator
Blow-by outlet hose
(1) Overview
(2) Layout
Page 271 of 796

07-6
2. FUNCTIONS OF LUBRICATION
1) Lubrication
It creates a viscous barrier between moving parts that reduces friction, which means less heat and
longer life for those parts. As a lubricant, oil must maintain a protective film to prevent metal-to-metal
contact. It must be fluid enough to allow easy starting and to circulate quickly through the engine, yet
remain thick enough at higher operating temperatures and speeds to provide adequate lubrication.
2) Cooling
Combustion heat and friction energy must be removed from the engine in order to prevent its
overheating. Most of heat energy is taken by the engine oil.
Clean oil passages, proper viscosity and low contamination provide sufficient flow rate of the engine oil
and effective cooling.
3) Sealing
It helps to seal the space between the pistons and the cylinder walls so that compression is more
effective and power is not lost during combustion.
4) Anti-corrosion
As a corrosion inhibitor, oil coats internal engine parts to prevent surface rust on the inside of the
engine which can be caused by blow-by products and water formed in combustion. It must also be
capable of neutralizing the acids that are formed by combustion blow-by and oil oxidation at high
temperatures.
5) Cleaning
The small particles of dirt or other contaminants are suspended in oil and carried away to be filtered
out. As a detergent, engine oil must be able to gather and suspend dirt and other contaminants until
the oil can leave them as it passes through the filter and returns to the internal engine environment.
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14-4
2) Designated Engine Oil for CDPF (Low Ash Oil)
Need to use the designated engine oil for CDPF
1.
The smoke from the vehicle may generate the particle material in the ambient air. CDPF is the
device to reduce the smoke by collecting and recycling it. To ensure the performance of
CDPF, the designated engine oil should be used.
The smoke including combusted sulfur in fuel cannot be recycled in CDPF. This smoke
generates the ash, resulting in clogging the filter. -
-
Advantages when using the designated engine oil for CDPF
2.
Reduces the amount of ash
Improves the fuel economy and reduces the CO2
Increases the life span of engine oil
Available for all engines (diesel and gasoline) -
-
-
-
Problems when using non-designated engine oil for CDPF
3.
Decreases the life span of engine oil due to accumulated ash in DPF (around 30%)
Decreases the fuel economy due to friction resistance, exhaust gas resistance and frequent
recycling process of DPF -
-
The fuel containing high sulfur may cause the same problems.
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15-46
(15) CDPF control
A. Overview
As the solution for environmental regulations and PM Particle Material) of diesel engine, the low
emission vehicle is getting popular. This vehicle is equipped with an extra filter to collect the soot and
burn it again so that the amount of PM in the exhaust gas passed through the DOC (Diesel Oxidation
Catalyst) is reduced. The CDPF (Catalyst & Diesel Particulate Filter) is an integrated filter including
DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter).
For details, refer to Chapter "CDPF".
B. Components
Oxygen sensorFront
EGT sensorCDPF
(DOC + DPF)Rear
EGT sensor
Differential pressure
sensorD20DTR ECUElectric throttle body