Brake booster and naster
cylinderVacuum pump
Pump capacity: 210 cc/rev
Camshaft speed: 375 to 3,000 rpm
Lubrication temperature: -40 to
Oil: 5W30
Drive type: Driven by exhaust
Camshaft sprocket
2. VACUUM PUMP
Vacuum pump generates the vacuum pressure and supplies it to EGR cooler bypass solenoid. This
pump is single vane type and displacement is 210 cc/rev. The lubrication oil is supplied through the hole
in hollow shaft.
Components
EGR cooler bypass valve
This valve is controlled by ECU.
When the engine is cooled, the
exhaust gas goes to combustion
chamber without passing through
EGR cooler because the valve is
closed by vacuum pressure.
(2) Di engine and its expected problems and remedies can be caused by
water in fuel
System supplement against paraffin separation
In case of Diesel fuel, paraffin, one of the elements, can be separated from fuel during winter and then
can stick on the fuel filter blocking fuel flow and causing difficult starting finally. Oil companies supply
summer fuel and winter fuel by differentiating mixing ratio of kerosene and other elements by region and
season. However, above phenomenon can be happened if stations have poor facilities or sell improper
fuel for the season. In case of DI engine, purity of fuel is very important factor to keep internal
preciseness of HP pump and injector.
Accordingly, more dense mesh than conventional fuel filter is used. To prevent fuel filter internal clogging
due to paraffin separation, SYMC is using fuel line that high pressure and temperature fuel injected by
injector returns through fuel filter to have an effect of built-in heater (see fuel system).
System supplement and remedy against water in fuel
As mentioned above, some gas stations supply fuel with excessive than specified water. In the
conventional IDI engine, excessive water in the fuel only causes dropping engine power or engine
hunting. However, fuel system in the DI engine consists of precise components so water in the fuel can
cause malfunctions of HP pump due to poor lubrication of pump caused by poor coating film during high
speed pumping and bacterization (under long period parking). To prevent problems can be caused by
excessive water in fuel, water separator is installed inside of fuel filter. When fuel is passing filter, water
that has relatively bigger specific gravity is accumulated on the bottom of the filter.
Water drain from water separator
If water in the separator on the fuel filter exceeds a certain level, it will be supplied to HP pump with fuel,
so the engine ECU turns on warning lamp on the meter cluster and buzzer if water level is higher than a
certain level.
Due to engine layout, a customer cannot easily drain water from fuel filter directly, so if a customer
checks in to change engine oil, be sure to perform water drain from fuel filter.
Water
separator
To separate the water from the fuel filter,
remove the fuel filter assembly first.
1719-00
3) Troubleshooting Sequence
The basic checks for intake system are as follows:
Basic Checks for Intake System
Make sure to replace or clean the air cleaner
element periodically. Otherwise, engine will be
derated or work abnormally because of low
intake air volume.
Unlike the fuel system, which is a closed
circuit, the intake system is an open circuit
system. Therefore any malfunction may occur
due to dust and dirt.
Most of the connections consist of hoses so
the system cannot withstand high temperature
and pressure. Also it can be deformed or
loosened easily because it is a clamp
mounting system. Thus, when checking the
engine, basic inspections, such as tightened
status check and visual inspection for hose,
etc., should be carried out in advance.
Other Checks for Intake System
If the intake system is free of any faults, check
for EGR and PCV oil separator.
2. INSPECTION
1) Cautions During Driving
The following lists cautions to take during test drive and on the turbocharger vehicle, which must be
considered during the operation.
It's important not to drastically increase the engine rpm starting the engine. It could make rotation at
excessive speed even before the journal bearing is lubricated and when the turbocharger rotates in
poor oil supply condition, it could cause damage of bearing seizure within few seconds.
If the engine is running radically after replacing the engine oil or oil filter brings poor oil supply
condition. To avoid this, it's necessary to start off after idling the engine for about 1 minute allowing oil
to circulate to the turbocharger after the replacement.
When the engine is stopped abruptly after driving at high speed, the turbocharger continues to rotate
in condition where the oil pressure is at '0'. In such condition, an oil film between the journal bearing
and the housing shaft journal section gets broken and this causes abrasion of the journal bearing due
to the rapid contact. The repeat of such condition significantly reduces life of the turbocharger.
Therefore, the engine should be stopped possibly in the idle condition. 1.
2.
3.
After string for long period of time during winter season or in the low temperature condition where the
fluidity of engine oil declines, the engine, before being started, should be cranked to circulate oil and
must drive after checking the oil pressure is in normal condition by idling the engine for few minutes.
1914-01
2) Inspection of Turbocharger
When problem occurs with the turbocharger, it could cause engine power decline, excessive discharge of
exhaust gas, outbreak of abnormal noise and excessive consumption of oil.
On-board Inspection 1.
Check the bolts and nuts foe looseness or missing
Check the intake and exhaust manifold for looseness or damage
Check the oil supply pipe and drain pipe for damages
Check the housing for crack and deterioration -
-
-
-
Inspection of turbine 2.
Remove the exhaust pipe at the opening of the turbine and check, with a lamp, the existence of
interference of housing and wheel, oil leakage and contamination (at blade edge) of foreign materials.
Interference: In case where the oil leak sign exists, even the small traces of interferences on the
turbine wheel mean, most of times, that abrasion has occurred on the journal bearing. Must inspect
after overhauling the turbocharger.
Oil Leakage: Followings are the reasons for oil leakage condition -
-
Idling for long period of time can cause oil leakage to the turbine side due to low pressure of exhaust
gas and the rotation speed of turbine wheel. Please note this is not a turbocharger problem.
Oil Drain Pipe Defect
In case where oil flow from the turbocharger sensor housing to the crank case is not smooth would
become the reason for leakage as oil builds up within the center housing. Also, oil thickens (sludge) at
high temperature and becomes the indirect reason of wheel hub section. In such case, clogging and
damage of the oil drain pipe and the pressure of blow-by gas within the crank case must be inspected.
Damages due to Foreign Materials
When the foreign materials get into the system, it could induce inner damage as rotating balance of
the turbocharger gets out of alignment. -
-Problems in engine: In case where the oil is smeared on inner wall section of the exhaust gas
opening.
Problems in turbocharger: In case where the oil is smeared on only at the exhaust gas
outlet section. *
*
1543-00
1. SPECIFICATION
The engine oil filter element should be changed at the same time with the engine oil.
Regularly check the engine oil level and add the engine oil if necessary.
Remember to check the engine oil level and shorten the cycle to replace the engine oil under
severe driving conditions. -
-
Severe Driving Condition
Frequent stop-and-go traffic, extended idling, short driving distance below 6 km, driving distance
below 16 km when the outside temperature remains below freezing
Driving in a hilly or mountainous terrain, sandy, or dusty area
High load driving such as trailer towing
Taxi, patrol service or delivery service (extended idling and excessive driving with low speed) -
-
-
-
Unit Specification
Oil pump Lubrication system Gear pump, forced circulation
Type Inscribed gear
Capacity 63 L at 4,000 rpm
Relief pressure
Oil filter Type Full flow/Paper element
Engine oil Specified oil SAE 5W30 (approved by MB SHEET 229.51)
Capacity (L) Min.: 4.5 L
Max.: 6.0 L
Service interval Change every 15,000 km or 12 months (But, shorten
the service interval under severe condition)
Oil injection
nozzleType Piston
Operating pressure 1.5bar
Closing pressure 1.0bar
Oil flow 4 L/min
Permissible pressure 10bar
Unit Specification
Oil pump Lubrication system Gear pump, forced circulation
Type Inscribed gear
Capacity 63 L at 4,000 rpm
Relief pressure
Oil filter Type Full flow/Paper element
Engine oil Specified oil SAE 5W30 (approved by MB SHEET 229.51)
Capacity (L) Min.: 4.5 L
Max.: 6.0 L
Service interval EU Change every 20,000 km or 12 months
(The service interval should be shortened under
severe conditions)
General Change every 15,000 km or 12 months
(The service interval should be shortened under
severe conditions)
Oil pressure
switch
1543-00
1. SYSTEM DESCRIPTION
1) Overview
The lubrication system supplies oil to each lubrication section to prevent friction and wear and to remove
heat from the friction part. As the engine runs, frictional heat is generated on each lubrication section. If
this condition persists, the bearing can be burned and stuck.
In other words, it creates an oil film on each sliding surface to convert solid friction to liquid friction in order
to minimize wear and prevent temperature increasing on the friction part.
For the D20DTF engine with no oil pressure switch, the engine ECU receives the low engine oil level
signal from the oil level sensor and communicates with the instrument cluster through the CAN
communication to turn on the warning lamp.
2) Components
Oil coolerOil dipstick gaugeOil pump
Oil filter moduleOil pressure switchOil pan
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.