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14-4
2. CAUTIONS
Standard pattern of soot accumulation ▶
(1) Abnormal Soot Accumulation (2) Normal Soot Combustion
Cautions to protect the catalyst filter ▶
Use the designated fuel only.
Observe the recommended service intervals of engine oil.
Check the engine oil level frequently and add if necessary.
Do not idle the vehicle unnecessarily.
Do not turn off the engine while the vehicle is running.
Do not shift the gear selector lever to neutral when going downhill.
Do not use improper engine oil or fuel additives.
Do not drive for a long time when the warning lamp is illuminated.
Make sure no flammable material, such as dry grass or tissue paper, contacts with the catalyst
filter while the vehicle is parked.
For the vehicles used in urban traffic, driving on the expressways for more than 1 hour at least
once per week is needed so that the PM inside CDPF isn't collected to one side only. -
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15-48
E. Cautions
Use only specified Engine Oil (approved by MB Sheet 229.51) for CDPF. -
Use only specified engine oil (Low Ash Oil) ▶
The vehicle equipped with CDPF should use specific engine oil to improve the engine
performance and fuel economy, and ensure the service life of CDPF. -
Issue with normal engine oil ▶
Sulfur, one of the contents of engine oil is burned and generates soot that is not regenerated
by the DPF. This remains on the filter as ashes and keeps accumulating. Eventually, this
ashes will block the filter. -
Benefit for specified engine oil ▶
Minimized the sulfur content of engine oil which reduces the service life.
Improved fuel economy and emission level of CO2 with high performance and low viscosity.
Increased service life of engine oil with high resistance to temperature. -
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Problems when using unspecified engine oil ▶
The service life of filter may be reduced by 30% or more by the ashes accumulated on the
filter.
The fuel economy may be reduced because of engine rolling resistance, frequent
regeneration of DPF. -
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These problems are also caused by oil with high sulfur content, such as tax exemption oil
and heating oil, etc. *
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01-31113-01
1. DESCRIPTION AND OPERATION
1) Cleanliness and Care
An automobile engine is a combination of many machined, honed, polished and lapped surfaces
with tolerances that are measured in the ten-thousanths of an inch.
When any internal engine parts are serviced, care and cleanliness are important.
A liberal coating of enigne oil should be applied to friction areas during assembly, to protect and
lubricate the surfaces on initial operation. Proper cleaning and protection of machined surfaces
and friction areas is part of the repair procedure.
This is considered standard shop practice even if not specifically stated.
Whenever valve train components are removed for service, they should be kept in order. They
should be installed in the same locations, and with the same mating surfaces, as when they were
removed.
Battery cables should be disconnected before any major work is performed on the engine. Failure
to disconnect cables may result in damage to wire harness or other electrical parts.
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01-4
2) On-engine Service
Disconnect the negative battery cable before removing or installing any electrical unit, or
when a tool or equipment could easily come in contact with exposed electrical terminals.
Disconnecting this cable will help prevent personal injury and damage to the vehicle. The
ignition must also be in LOCK unless otherwise noted. -
Any time the air cleaner is removed, the intake opening should be covered. This will protect
against accidental entrance of foreign material, which could follow the intake passage into
the cylinder and cause extensive damage when the engine is started. -
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01-111113-01
2) Compression Pressure Test
Standard Service Data ▶
A9912 0012B (001 589 76 21 00) Compression Pressure Tester -
Measuring Procedure ▶
Warm the engine up to normal operating temperature.
Remove the spark plugs using the spark plug wrench.
Place the diagram sheet to compression pressure tester A9912 0012B (001 589 76 21 00).
Connect the adaptor to compression pressure tester A9912 0012B (001 589 76 21 00)
and install it into the spark plug hole.
Crank the engine approx. eight revolutions by using the start motor.
Compare the measurements of compression pressure tester A9912 0012B (001 589 76 21
00) with the specifications.
Measure the compression pressure of the other cylinders in the same way.
If measured value is not within the specifications, perform the cylinder pressure leakage
test. -
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Discharge the combustion residues in the cylinders before testing the compression
pressure.
Apply the parking brake before cranking the engine. -
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Page 383 of 828

04-72112-01
4) Water Pump
The belt-driven centrifugal water pump consists of an impeller, a drive shaft, and a belt pulley.
The impeller is supported by a completely sealed bearing.
The water pump is serviced as an assembly and, therefore, cannot be disassembled.
5) Thermostat
A wax pellet-type thermostat controls the flow of the engine coolant through the engine cooling
system. The thermostat is mounted in the thermostat housing to the front of the cylinder head.
The thermostat stops the flow of the engine coolant from the engine to the radiator to provide
faster warm-up, and to regulate the coolant temperature. The thermostat remains closed while the
engine coolant is cold, preventing circulation of the engine coolant through the radiator. At this
point, the engine coolant is allowed to circulate only throughout the heater core to warm it quickly
and evenly.
As the engine warms, the thermostat opens. This allows the engine coolant to flow through the
radiator wherethe heat is dissipated. This opening and closing of the thermostat permits enough
engine coolant to enter the radiator to keep the engine within proper engine temperature operating
limits.
The wax pellet in the thermostat is hermetically sealed in a metal case. The wax element of the
thermostat expands when it is heated and contracts when it is cooled.
As the vehicle is driven and the engine warms, the engine coolant temperature increases. When
the engine coolant reaches a specified temperature, the wax pellet element in the thermostat
expands and exerts pressure against the metal case, forcing the valve open. This allows the
engine coolant to flow through the engine cooling system and cool the engine.
As the wax pellet cools, the contraction allows a spring to close the valve.
The thermostat begins to open at 82°C(180 °F) and is fully open at 95°C(203°F). The thermostat
closes at 80°C (176°F).
6) Electric Cooling Fan
Keep hands, tools, and clothing away from the engine cooling fans to help prevent personal
injury.
This fan is electric and can turn on even when the engine is not running. -
If a fan blade is bent or damaged in any way, no attempt should be made to repair or reuse
the damaged part. A bent or damaged fan assembly should always be replaced with a new
one to prevent possible injury. -
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05-6
(2) Cold Cranking Amperage
The cold cranking amperage test is expressed at a battery temperature of -18°C(0°F).
The current rating is the minimum amperage, which must be maintained by the battery for 30
seconds at the specified temperature, while meeting a minimum voltage requirement of 7.2 volts.
This rating is a measure of cold cranking capacity.
The battery is not designed to last indefinitely. However, with proper care, the battery will provide
many years of service. If the battery tests well, but fails to perform satisfactorily in service for no
apparent reason, the following factors may point to the cause of the trouble:
Vehicle accessories are left on overnight.
Slow average driving speeds are used for short periods.
The vehicle's electrical load is more than the generator output, particularly with the addition of
aftermarket equipment.
Defects in the charging system, such as electrical shorts, a slipping generator belt, a faulty
generator, or a faulty voltage regulator.
Battery abuse, including failure to keep the battery cable terminals clean and tight or a loose
battery hold-down clamp.
Mechanical problems in the electrical system, such as shorted or pinched wires. ·
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3) Charging Time Required
The time required to charge a battery will vary depending upon the following factors:
Size of Battery - A Completely discharged large heavy-duty battery required more than twice
the recharging time as a completely discharged small passenger car battery. ▶
<007b008c00940097008c00990088009b009c0099008c00470054004700680047009300960095008e008c00990047009b00900094008c0047009e00900093009300470089008c00470095008c008c008b008c008b0047009b00960047008a008f0088009900
8e008c00470088009500a0004700890088009b009b008c0099>y at -18°C(0°F) than at
27°C(80°F).
When a fast charger is connected to a cold battery, the current accepted by the battery will be
very low at first.
The battery will accept a higher current rate as the battery warms. ▶
Charger Capacity - A charger which can supply only 5 amperes will require a much longer
charging period than a charger that can supply 30 amperes or more. ▶
State-of-Charge - A completely discharged battery requires more than twice as much charge
as a onehalf charged battery.
Because the electrolyte is nearly pure water and a poor conductor in a completely discharged
battery, the current accepted by the battery is very low at first. Later, as the charging current
causes the electrolyte acid content to increase, the charging current will likewise increase. ▶
Page 397 of 828
05-10
9) Starting System
The engine electrical system includes the battery, the ignition, the starter, the generator, and all
the related wiring.
Diagnostic tables will aid in troubleshooting system faults. When a fault is traced to a particular
component, refer to that component section of the service manual.
The starting system circuit consists of the battery, the starter motor, the ignition switch, and all the
related electrical wiring.
All of these components are connected electrically.