Page 32 of 118

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Cylinder head gasket
11
11 - 6
Cylinder head gasket
SPECIAL TOOLING REQUIRED
Mot. 251 -01 Dial gauge support
Mot. 252 -01 Pressure plate to measure
piston protrusion
Mot. 1054 TDC setting pin
Mot. 1159 Tool for holding engine on
subframe
Mot. 1202 -01
Hose clip pliers
Mot. 1202-02
Mot. 1387 Tool for checking the automatic
tensioner centreline
Mot. 1448 Long nose pliers for hose clips
Mot. 1453 Engine support
Mot. 1505 Tool for measuring belt tension
Mot. 1453 Timing belt pretensioning
torque tool
ESSENTIAL SPECIAL TOOLING
Cylinder head testing equipment
14 torx socket
Angular tightening wrench
55 torx socket
REMOVAL
Put the vehicle on a 2 post lift.
Disconnect the battery.
Remove the engine undertray.
Drain the cooling circuit through the lower radiator
hose.
Remove:
– the timing belt (see method described in section 11,
"Timing belt").
– the two PAS pipe mountings on the right hand sub-
frame. TIGHTENING TORQUES (in daN.m and/or ˚)
Tension roller nut 5
Crankshaft pulley bolt 2 + 115˚ ± 15˚
Suspended mounting cover bolt 6.2
Suspended mounting limiter bolt 6.2
Torque reaction arm 6.2
Wheel bolts 9
Page 38 of 118
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Cylinder head gasket
11
11-12
REFITTING (special notes)
Fit the cylinder head gasket. This is centred by two
dowels.
Bring the pistons to mid-stroke position to prevent
them from coming into contact with the valves as the
cylinder head is tightened.
Centre the cylinder head on the dowels.
Lubricate the threads and under the heads of the
mounting bolts.
Tighten the cylinder head using an angular tightening
wrench (see section '07 "Tightening the cylinder
head").
Tightening procedure for the automatic tensioner
mounting
Offer up the three touching bolts then apply a torque of
2.5 daN.m respecting the order shown below.
Refitting is the reverse of removal.
Refit the timing belt, (see procedure described in
section 11 "Timing belt").
Fill and bleed the cooling circuit, (see section 19
"Filling and Bleeding").
To reprime the diesel circuit, consult section 13, "Fuel
filter".
PRF1102
Page 42 of 118
Downloaded from www.Manualslib.com manuals search engine TURBOCHARGING
Turbocharger
12
12-4
Turbocharger
SPECIAL TOOLING REQUIRED
Elé. 1294 -01 Tool for removing windscreen
wiper arms
REMOVAL
NOTE: to slacken the turbocharger mounting nuts
more easily on the exhaust manifold, it is useful to
spray a releasing agent on the nuts when still hot, just
before removal.
Disconnect the battery.
Remove the engine cover.
From below
Remove:
– the engine undertray,
– the mounting stay (5),
– the two bolts fixing the turbo oil return pipe (7) to the
engine,
– the lower turbo mounting nut on the exhaust
manifold.
Disconnect the turbo pre-catalytic converter (6)
(priming catalytic converter). TIGHTENING TORQUES (in daN.m )
Turbo mounting nuts (1) 2.4
Oil inlet connection (4) 2.4
Oil inlet connection (3) 2.6
Oil return connection bolt (7) 1.2
Primer catalytic converter mounting bolt
to turbo (2) 2.4
16156R1
16155R1
Page 47 of 118
Downloaded from www.Manualslib.com manuals search engine FUEL MIXTURE
Manifolds
12
12-9
FUEL MIXTURE
Manifolds
REMOVAL
NOTE: Removal of the manifolds requires that you
remove the turbocharger (see section 12
"Turbocharging"). The two manifolds cannot be
removed separately.
Disconnect:
– the battery,
– the air inlet pipe from the intake manifold (2),
– the pipe leading to the pressure sensor on the
manifold (1),
– the EGR (5) solenoid valve.Remove (for the Scénic):
– the windscreen wiper arms,
– the scuttle panel,
– the bulkhead panel,
– the air unit,
– the turbocharger. TIGHTENING TORQUES (in daN.m )
Manifold mounting stud 0.8
Manifold mounting stud 2.8
EGR valve mounting bolt 2.1
16869R2
12415R1
Page 50 of 118
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Priming catalytic converter
12
12-12
Priming catalytic converter
REMOVAL
Put the vehicle on a two post lift.
Disconnect the battery.
Remove the cover and the under body protection.
Disconnect the exhaust downpipe.Remove (for the Scénic) :
– the windscreen wiper arms using tool Elé. 1294-01,
– the scuttle panel,
– the bulkhead panel,
Disconnect the flow meter and remove the air unit.
Remove:
– the priming catalytic converter mounting stay,
– the mounting nuts,
– the pre-catalytic converter. TIGHTENING TORQUES (in daN.m )
Priming catalytic converter mounting nuts
(pre-catalytic converter) 2.4
Lower mounting bolt 2.4
Priming catalytic converter stay bolt 6
16156S
11020R
11036R2
Page 55 of 118

Downloaded from www.Manualslib.com manuals search engine DIESEL EQUIPMENT
Special notes
13
13-4
OPERATION
The common rail direct high pressure injection system is a sequential diesel injection system (based on the
operation of multipoint injection for petrol engines).
This new injection system reduces operating noise, lowers the quantity of polluting gas and particles and produces
significant engine torque at low engine speeds thanks to a pre-injection procedure.
The low pressure pump (also called the supercharging pump) supplies the HP pump, through the filter with pressure
of between 2.5 and 4 bars.
The HP pump generates the high pressure sent to the injection rail. The pressure regulator located on the pump
modulates the value of the high pressure via the computer. The rail supplies each injector through a steel pipe.
The computer:
– determines the value of injection pressure necessary for the engine to operate well and then controls the pressure
regulator. It checks that the pressure value is correct by analysing the value transmitted by the pressure sensor
located on the rail,
– determines the injection time necessary to deliver the right quantity of diesel and the moment when injection should
be started,
– controls each injector electrically and individually after determining these two values.
The injected flow to the engine is determined depending on:
– the duration of injector control,
– the injector opening and closing speed,
– the needle stroke (determined by the type of injector),
– the nominal injector hydraulic flow (determined by the type of injector),
– the high pressure rail pressure controlled by the computer.
FOR ANY INTERVENTION IN THE HIGH PRESSURE INJECTION SYSTEM YOU MUST RESPECT THE
CLEANING AND SAFETY ADVICE SPECIFIED IN THIS DOCUMENT.
Page 56 of 118

Downloaded from www.Manualslib.com manuals search engine DIESEL EQUIPMENT
Special notes
13
13-5
POST-REPAIR CHECK
A fuel cock is fitted to the fuel filter at the level of the diesel return pipe leading to the tank. It should be in open
position for normal operation.
However, to carry out a circuit reignition after an intervention, a filter change or a fuel fault, you should:
– close the fuel cock,
– start the low pressure pump by switching on the ignition several times,
– start the engine,
– OPEN THE FUEL COCK (the valve is open when the two coloured lines are aligned).
NOTE: certain vehicles are not fitted with a fuel cock. In this case, ignore this operation.
IMPORTANT: the engine must not run with diesel containing more than 10 % diester.
The system can inject the diesel into the engine up to a pressure of 1350 bars. Before any intervention, check
that the injector rail is depressurised.
It is absolutely vital that you observe the tightening torque:
– of the high pressure pipes,
– of the injector on the cylinder head,
– of the pressure regulator,
– of the pressure sensor.
When the high pressure pump, injectors, supply, return and high pressure output unions are repaired or
removed, the bores should be fitted with new and appropriate core seals to avoid impurities.
When replacing a high pressure pipe, the following procedure should be observed:
– remove the high pressure pipe,
– fit the cleanliness plugs,
– loosen the high pressure rail and the pump/rail pipe,
– fit the high pressure pipe,
– tighten the injector side union to torque,
– tighten the connection on the high pressure pump side to torque,
– tighten the high pressure rail fastenings to torque.
– tighten the pump/rail pipe to torque (pump side first).
It is prohibited to remove the interior of the pump.
It is vital that you replace the fuel return pipe placed on the injectors during removal.
The diesel temperature sensor is not removable. It is part of the fuel return rail.
It is forbidden to loosen a high pressure pipe connection when the engine is running.After any operation, check that there are no diesel leaks. Start the engine at idling speed until the fan starts up,
then accelerate several times under no load.
Page 69 of 118
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Heater plugs
13
13-18
Heater plugs
The resistance of a heater plug is 0.6 Ω.
Plugs may be removed without having to open the
high pressure circuit.
REMOVAL
Unclip the plug connector.
Clean the plug exterior to avoid any dirt entering the
cylinder.
Undo and then remove the plugs.
To undo the plug on cylinder 4 use a 10 mm long radio
socket attached to a universal joint. Once the plug is
loosened use a pipe socket to unscrew it completely.
REFITTING
Proceed in the reverse order to removal.TIGHTENING TORQUES (in daN.m)
Heater plug 1.5
15762S