Iveco Daily Euro 4. Manual — part 71
88686
88685
88687
88688
Figure 295
Figure 296
Figure 297
Figure 298
HEAT EXCHANGER SECTIONS
Oil flow from heat exchanger to oil filter
Oil flow from oil filter to cylinder block
Oil flow from cylinder block to heat exchanger
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Figure 299
540480
Oil vapour recirculation (Blow-by)
Part of the gas produced by the combustion during the
engine operation blows by the piston snap ring ports, in the
oil sump, and mixes with the oil vapours present in the oil
sump. This mixture, conveyed from the chain compartment
to the top, is partially separated from the oil by means of a
device situated on the top side of the distribution cover and
is introduced in the air suction system. This device consists
mainly of a rotating filter (3), fit flush on the stem (1), a high
pressure/shaft control and a cover (2) where the valves (4
and 5), usually closed, are fitted. The diaphragm valve (4)
regulates the partially purified mixture and keeps the pressure
inside the chain compartment around a value of ~ 10
÷ 15
mbar.
The umbrella valve (5) discharges some of the oil still present
in the mixture coming from the filter (3) in the chain
compartment and the oil condenses in the chamber (6).
Operation
The mixture which passes through the rotating filter (3) is
partially purified from the oil particles, as a result of
centrifugation, and so these particles condense on the cover
walls to return to the lubrication circuit. The resulting purified
mixture is let in through the stem holes (1) and the
diaphragm valve consensus (4) inside the air vent upstream
of the turbocharger. The opening/closing of the valve (4)
depends mainly in the ratio between the pressure operating
the diaphragm (4) and the depression below it. The oil still
present in the mixture coming from the rotating filter (3) and
which condenses in the chamber (6) is drained into the chain
compartment through the umbrella valve (5), when the
pressure that keeps it closed drops as a result of the engine
stop.
88062
Gas with oil level above 10 g/h
Gas with oil level ~ 0,2 g/h
Condensed oil returning to the oil sump
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Figure 300
5432
COOLING
Description
The engine cooling system is the type with forced circulation
in a closed circuit. It comprises the following parts:
- An expansion tank whose plug has two valves
incorporated in it: an outlet and an inlet, which govern
the pressure of the system.
- A coolant level sensor at the base of the expansion tank.
- A pressure switch (3), of normally closed type (calibrated
at 0.4 bar, absolute pressure 1.4 bar), located on
expansion tank and connected to EDC central unit,
protects engine against overheating caused by cooling
system failure. Where coolant temperature exceeds a
certain threshold and pressure inside expansion tank is
lower than 0.4 bar, EDC central unit reduces engine
performance by changing fuel flow rate (De-rating) until
engine goes off.
- An engine cooling module to dissipate the heat taken
from the engine by the coolant with a heat exchanger
for the intercooler.
- A heat exchanger to cool the lubricating oil.
- A centrifugal water pump incorporated in the crankcase.
- An electric fan comprising an electromagnetic coupling
on whose shaft a hub turns idle that is fitted with an
axially mobile metal plate on which is mounted the
impeller.
- A 3-way thermostat governing the circulation of the
coolant.
Operation
The water pump driven by a poly-V belt by the crankshaft
sends coolant into the crankcase and with a greater head into
the cylinder head.
When the coolant temperature reaches and exceeds the
working temperature, it causes the thermostat to open and
the fluid is channelled from here to the radiator and cooled
by the fan.
The pressure in the system due to the change in temperature
is governed by the outlet (2) and inlet (1) valves incorporated
in the expansion tank filler plug (detail A).
The outlet valve (2) has a twofold function:
- to keep the system slightly pressurized so as to raise the
boiling point of the coolant;
- to discharge into the atmosphere the excess pressure
produced in case of high coolant temperatures.
The function of the inlet valve (1) is to permit transferring the
coolant from the expansion tank to the radiator when a
lower pressure is created in the system due to the reduction
in volume of the coolant as a result of its temperature
lowering.
Outlet valve opening 1
± 0.1 kg/cm
2
.
Inlet valve opening 0.005 — 0.02 kg/cm
2
.
107753
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CROSS-SECTION OF THE ELECTROMAGNETIC JOINT
Characteristics
Transmissible torque at 20
°C with clutch run in
85 Nm
Voltage
12 Volts
Power input at 20
°C
48 W
The electric fan control relay is activated or deactivated
according to the temperatures of: the engine coolant, the fuel
supercharging air and the pressure of the air conditioner fluid
(if present).
Turbocharging air temperature
It activates at > 75
°C and deactivates at < 65°C.
Coolant temperature (if the sensor is not defective)
It activates at > 96
°C and deactivates at < 84°C.
Fuel temperatures
(if the coolant temperature sensor is acknowledged to be
defective by the EDC control unit)
It activates at > 20
°C and deactivates at < 10°C.
With climate control system
With pressure in the system
it turns on
18.5
± 0.98 bar
it turns off
14.58
± 0.98 bar
107754
Figure 301
The water pump cannot be overhauled. In case of coolant
leaking from the seal or damage, it must be replaced.
543212
Electromagnetic pulley
543210
Water pump
LONGITUDINAL CROSS-SECTION OF THE
WATER PUMP
1. Pump casing — 2. Pump drive shaft together with
bearing — 3. Seal — 4. Impeller.
Figure 302
107755
The by-pass thermostat (1) needs no adjustment.
If there is any doubt about its operation, replace it.
The thermostat casing is fitted with the thermometric
switch/transmitter and water temperature sensor.
Valve travel at 79 + 2 5C = 0.1 mm
Valve travel at 94 + 2 5C, min. 7 mm
543250
Thermostat
Figure 303
107756
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