1999 LAND ROVER DEFENDER sensor

ENGINE
15
REPAIR
NOTE: Non EU3 model illustrated.
9.Disconnect fuel hoses, tank to fuel cooler and
connector block on cylinder head.
CAUTION: Plug the connections.
10.Disconnect fuel hose from fuel cooler and secure
to connector block on cylinder head. This to
prevent contamination of the fuel system.
11.Release servo vacuum pipe, remove 4 bolts and
remove fuel cooler.
12.Release servo vacuum pipe from engine rear
cover clips and vacuum pump.
NOTE: Non EU3 model illustrated.
13.Disconnect vacuum hose from EGR valve.
14.Release EGR vacuum hose from vacuum pipe.
15.Disconnect multiplug from condensor cooling
fan.
NOTE: Non EU3 model illustrated.
16.Disconnect multiplugs from EGR solenoid, inlet
manifold sensor and injector harness.
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12ENGINE
16
REPAIR
NOTE: Non EU3 model illustrated.
17.Disconnect multiplug from fuel temperature
sensor.
18.Disconnect multiplug from CKP sensor. Remove
bolt securing CKP sensor, remove sensor and
discard’O’ring.
CAUTION: If fitted:- Retain CKP sensor
spacer.
19.Disconnect 4 glow plug leads.
20.Remove nut securing alternator lead and
disconnect multiplug.
NOTE: Non EU3 model illustrated.
21.Remove 2 bolts securing engine harness to
camshaft carrier.
22.Disconnect A/C compressor and ECT sensor
multiplugs.
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12ENGINE
18
REPAIR
35.Remove 2 bolts and remove acoustic cover from
rear of cylinder head.
36.FitLRT-12-138to suitable lifting chains and
connect to lifting eyes on engine.
37.Remove 2 nuts from RH and LH front engine
mountings.
38.Fit trolley jack to support gearbox.
39.With assistance raise chains and remove engine
from vehicle.Refit
40.With assistance, raise engine from bench and
position in vehicle.
41.With assistance, align engine to gearbox input
shaft.
42.Position 2 upper bolts securing gearbox housing
to engine and tighten to50 Nm (37 lbf.ft).
43.Lower engine onto mountings and tighten nuts to
85 Nm (63 lbf.ft).
44.RemoveLRT-12-138from engine.
45.Fit and tighten bolt securing engine closing panel
to gearbox.
46.Raise vehicle on ramp.
47.Fit bolts securing gearbox housing to engine and
tighten to50 Nm (37 lbf.ft).
48.Lower ramp.
49.Fit acoustic cover to rear of cylinder head and
tighten bolts.
50.Position coolant hose to engine oil cooler and
secure clip.
51.Position PAS pump and tighten bolts to25 Nm
(18 lbf.ft).
52.Position PAS pulley and tighten bolts to25 Nm
(18 lbf.ft).
53.Position A/C compressor and tighten bolts to25
Nm (18 lbf.ft).
54.Route engine harness beneath inlet manifold
and connect multiplugs to oil pressure switch,
A/C compressor, and ECT sensor.
55.Fit and tighten bolts securing engine harness to
camshaft carrier.
56.Connect multiplug to alternator.
57.Connect battery lead to alternator and tighten
nut.
58.Clean CKP sensor and mating face.
CAUTION: If originally fitted:- Fit spacer to
CKP sensor.
59.Using a new’O’ring, fit CKP sensor, tighten bolt
to10 Nm (7 lbf.ft).
60.Connect CKP sensor multiplug.
61.Connect multiplugs to EGR solenoid, inlet
manifold sensor, injector harness, fuel
temperature sensor and CKP sensor.
62.Connect glow plug leads.
63.Connect multiplug to condensor cooling fan.
64.Connect vacuum hose to EGR valve.
65.Connect EGR vacuum hose to vacuum pipe.
66.Position pipe to vacuum pump and secure pipe
to acoustic cover clips.
67.Position fuel cooler. Apply Loctite 242 to bolts
and tighten to18 Nm (13 lbf.ft).
68.Disconnect fuel hose from connector block and
connect to fuel cooler.
69.Connect fuel hoses to fuel cooler and connector
block on cylinder head.
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ENGINE
1
OVERHAUL GASKET - INLET MANIFOLD
Service repair no - 30.15.08.01
Remove
NOTE: The following procedure covers
both EU3 and non EU3 engines
NOTE: EU3 Engine in main illustration, Pre
EU3 condition shown in inset.
1.Remove and discard 2 Allen screws securing
EGR pipe or EGR cooler to exhaust manifold.
2.Remove bolt securing EGR pipe to cylinder
head, (if fitted)
3.Disconnect multiplug from IAT and MAP sensor.
4.Remove 4 bolts securing fuel cooler to inlet
manifold. and remove cooler.
5.Remove bolt securing engine dipstick tube to
camshaft carrier.
6.Release and remove engine dipstick tube.
7.Remove’O’ring from dip stick tube.
8.Disconnect 4 leads from glow plugs.
9.Remove 2 nuts and 8 bolts and remove inlet
manifold.
10.Remove manifold gasket.Refit
1.Clean inlet manifold and mating face, clean
mating faces of EGR pipe, exhaust manifold and
EGR cooler (if fitted).
2.Fit new gasket.
3.Position inlet manifold and working from the
centre outwards, fit inlet manifold nuts and bolts
and tighten to25 Nm (18 lbf.ft).
4.Connect glow plug leads.
5.Clean engine dipstick tube.
6.Fit new’O’ring to dipstick tube.
7.Fit engine dipstick tube to camshaft carrier and
tighten bolt to10 Nm (7 lbf.ft).
8.Position fuel cooler and tighten bolts to25 Nm
(18 lbf.ft).
9.Connect multiplug to IAT and MAP sensor.
10.Position EGR pipe or EGR cooler to exhaust
manifold and using new Allen screws tighten to
10 Nm (7 lbf.ft).
11.Fit EGR pipe clamp to cylinder head, (if fitted)
and tighten bolt to10 Nm (7 lbf.ft).
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ENGINE
3
OVERHAUL GASKET - CYLINDER HEAD
Service repair no - 12.29.02.01
Remove
CAUTION: The following procedures
should only be carried out when cylinder
head is to be overhauled; for replacement
of cylinder head gasket only, see Repairs section -
Gasket - Cylinder head.
NOTE: The following procedure covers
both EU3 and non EU3 engines
1.Remove exhaust manifold gasket.See
MANIFOLD AND EXHAUST SYSTEM, Repair.
2.Remove inlet manifold gasket.See MANIFOLD
AND EXHAUST SYSTEM, Repair.
3. Models with EGR cooler:Remove and discard
2 Allen screws securing EGR pipe to cooler.
4.Progressively loosen then remove 13 bolts
securing camshaft cover, remove cover; remove
and discard gasket.
5.Remove isolators and sealing washers from
cover.
6.Disconnect injector multiplug from camshaft
carrier.
7.Disconnect multiplug from ECT sensor.
8.Remove bolt securing alternator strap bracket to
cylinder head.
9.Set engine to TDC firing - No. 1 cylinder -
coloured links on timing chain are aligned with
timing mark on camshaft sprocket.
10.Fit timing pinLRT-12-058into slot in camshaft.
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12ENGINE
6
OVERHAUL 14.Clean fixed guide Allen screw and apply Loctite
242 to screw threads.
15.Fit fixed timing chain guide Allen screw and
tighten to25 Nm (18 lbf.ft).
16.Clean timing chain tensioner and fit new sealing
washer.
17.Fit timing chain tensioner and tighten to45 Nm
(33 lbf.ft).
18.Tighten camshaft sprocket bolts to36 Nm (27
lbf.ft).
19.Remove toolLRT-12-058from camshaft.
20.Lubricate a new’O’ring with engine oil and fit to
camshaft sprocket access plug.
21.Fit camshaft sprocket access plug.
22.Clean alternator/vacuum pump oil feed hose
union.
23.Lubricate a new’O’ring with engine oil and fit to
alternator/vacuum pump hose union.
24.Fit and tighten alternator/vacuum pump oil hose
union to10 Nm (7 lbf.ft).
25.Fit bolt securing alternator strap bracket to
cylinder head and tighten to25 Nm (18 lbf.ft).
26.Connect multiplugs to ECT sensor and EUIs.
CAUTION: Following cylinder head
overhaul, it will be necessary, before
fitting the camshaft cover, to adjust the
fuel injector rockers using the following
procedures:
27.Rotate engine clockwise until No. 1 EUI lobe is
at full lift.
28.Tighten No.1 rocker adjusting screw until the EUI
plunger is felt to’bottom out’.
29.Loosen rocker adjusting screw 1 complete turn
to give EUI plunger the required bump clearance
and tighten rocker adjusting screw locknut to16
Nm (12 lbf.ft).
CAUTION: Ensure screw does not turn as
locknut is tightened.30.Carry out above procedures for the remaining 4
rocker arms.
31.After completion of rocker adjustment, slowly
rotate engine clockwise 2 complete turns by
hand to ensure that no EUI’s are bottoming out
on their plungers.
32.Clean camshaft cover and mating face.
33.Fit new sealing washers and isolators as
necessary to camshaft cover.
34.Fit new camshaft cover gasket to cover.
CAUTION: Gasket must be fitted dry.
35.Fit camshaft cover to camshaft carrier, fit bolts
and working from the centre outwards, tighten
bolts to10 Nm (7 lbf.ft).
36.Fit inlet manifold gasket.See MANIFOLD AND
EXHAUST SYSTEM, Repair.
37.Fit exhaust manifold gasket.See MANIFOLD
AND EXHAUST SYSTEM, Repair.
38. EGR cooler fitted:-Position EGR pipe to cooler,
fit new Allen screws and tighten to10 Nm (7
lbf.ft).
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17EMISSION CONTROL
8
DESCRIPTION AND OPERATION EXHAUST GAS RECIRCULATION
The exhaust gas recirculation (EGR) valve permits a controlled amount of exhaust gas to combine with the fresh
air entering the engine. The exhaust gas reduces the combustion temperature by delaying the fuel burning rate,
which assists in reducing the quantity of oxides of nitrogen.
On EU3 models, an EGR cooler is employed to further reduce the combustion temperature. By passing the
exhaust gas through a bundle of pipes flooded by coolant, the density of the exhaust gas going into the engine is
increased. This process further reduces the amount of NO
2in the exhaust.
Recirculation of too much exhaust gas can result in higher emissions of soot, HC and CO due to insufficient air.
The recirculated exhaust gas must be limited so that there is sufficient oxygen available for combustion of the
injected fuel in the combustion chamber. To do this the ECM is used to control the precise quantity of exhaust gas
to be recirculated in accordance with the prevailing operating conditions. Influencing factors include:
The mass of air flow detected by the MAF sensor.
The ambient air temperature detected by the AAP sensor. This is used to initiate adjustments to reduce the
amount of smoke produced at high altitudes.
The mass of air flow detected by the MAF sensor.
The ambient air temperature detected by the AAP sensor. This is used to initiate adjustments to reduce the
amount of smoke produced at high altitudes.
Other factors which are taken into consideration by the engine management system for determining the optimum
operating condition include:
Manifold inlet air temperature
Coolant temperature
Engine speed
Fuel delivered
The main components of the EGR system are as follows.
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17EMISSION CONTROL
14
DESCRIPTION AND OPERATION EGR SYSTEMS
There are two types of exhaust gas recirculation system used with the Td5 engine dependent on legislation and
market requirements, these are type 1 and type 2.
Type 1 EGR system is fitted to all Td5’s built up to the introduction of 2002 MY, except for Japanese specification
vehicles.
Type 2 EGR system is fitted to all Japanese specification vehicles and was introduced into European markets for
2002 MY to meet EU3 emission requirements. An additional feature introduced at 2002 MY is the EGR cooler,
which is bolted to the front of the cylinder head.
EGR System - Type 1
This EGR system features a modulator which is electrically controlled to modulate a vacuum source to the EGR
valve. The controlled vacuum opens the valve by the amount required to ensure the optimal proportion of exhaust
gas is allowed through to the inlet manifold to be combined with the fresh air intake. Control feedback is achieved
by monitoring the mass of fresh air flowing through the MAF sensor.
EGR modulator operation is controlled by a signal from the ECM, which determines the required amount of EGR
needed in response to inputs relating to air flow and engine operating and ambient conditions. The ECM is
low-side driven, sinking current returned from the vacuum modulator for switching operating condition.
The exhaust gases are routed from the exhaust manifold through a shaped metal pipe which connects to the
underside of the EGR valve. The pipe is held securely in position to the front of the cylinder head using a clamp
bracket. The EGR pipe is attached to a mating port at the front end of the exhaust manifold using 2 Allen screws,
and at the EGR valve assembly by a metal band clamp. The 2 Allen screws should be replaced every time the
EGR pipe is removed.
CAUTION: Extreme caution should be exercised when removing and refitting the EGR pipe to
avoid damage.
When a vacuum is applied to the EGR suction port, it causes a spindle with sealing disc (EGR valve) to be raised,
thus opening the port at the EGR pipe to allow the recirculated exhaust gas to pass through into the inlet manifold.
The valve is spring loaded so that when the vacuum is removed from the suction port the valve returns to its rest
position to tightly close the exhaust gas port.
By controlling the quantity of recirculated exhaust gas available in the inlet manifold, the optimum mix for the
prevailing engine operating conditions can be maintained. This ensures the intake gas to the combustion
chambers will have burning rate properties which will reduce NO
Xemissions to an acceptable level. Normally, full
recirculation is only applicable when NO
Xemissions are most prevalent.
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