timing JAGUAR X308 1998 2.G Workshop Manual

Installation

15. Remove the primary ch ain tensioner blade.
1. Remove the pivot bolt which secures the tensioner blade.
2. Remove the tensioner blade.
16. Disconnect the primary chain from the VVT unit and the
crankshaft sprocket, and remove it completely.
17. Do not tamper with the three bolts which secure the VVT
mechanism to the sprockets. It is sealed at the factory to the
correct valve timing specificatio n for the engine and is supplied
only as a complete unit.

18. Remove the VVT unit.
1. Remove the securing bolt from both the VVT unit and
the exhaust cam sprocket.
2. Remove the VVT unit, exhaust sprocket and secondary chain as an asse mbly (release the chain
from the tensioner which is still secured to the
cylinder head).
Remove the secondary chain from the VVT unit and the
sprocket.
19. Clean and inspect all relevant components.

1. Push the tensioner piston (secon dary chain) into the body to
provide clearance for fitting.
1. Insert a thin rigid wire th rough the hole in the end of
the tensioner piston to displace the ball from the non-
return valve seat.
2. With the wire in position, press the piston fully into the tensioner body.
Remove the wire.
2. Fit the VVT unit to the engine.
Assemble the VVT unit, the exhaust camshaft sprocket
and the secondary chain, in pr eparation for fitting to the
engine.
1. Fit the above assembly to the camshafts with the chain correctly positioned over the tensioner; VVT
unit to the inlet and the sprocket to the exhaust.
2. Fit, but do not tighten, each bolt which secures the VVT unit and the exhaust sprocket to the camshafts.

3. Fit the chain tensioning tool 303 - 532 to the exhaust camshaft
sprocket.
Reposition the sprocket (and the VVT unit) for the most
advantageous position for use of the tool.
Remove the tool.

4. Refit the primary timing chain.
1. Fit the primary chain to position over the crankshaft sprocket and the VVT unit sprocket. There must be no
slack on the drive side of the primary chain.
2. The VVT unit must not be rotated on the camshaft

5. Fit the primary chain tensioner blade.
1. Position the tensioner blade to the cylinder block.
2. Fit the retaining / pivot bolt and tighten it to 12-16 Nm.
6. Refit the primary chain tensione r assembly. Refer to Operation
12.65.54 in this Section.
Use a wedge 303 - 533 (or two if required) between the
primary chain tensioner and te nsioner blade, to take up
the slack in the chain.

7. Tighten the exhaust camshaft sprocket securing bolt.
1. Fit the chain tensioner tool 303 - 532 to the sprocket holes.
Apply force to the tool in an anti-clockwise direction to
tension the chain on its drive side.
2. Whilst applying the opposing force to the sprocket and chain, tighten the sprock et securing bolt to 115 -
125 Nm.

8. Tighten the VVT unit securing bolt.
1. Whilst still applying the opposing force to the
sprocket and chain (using 303 - 532), check that the
wedges are still in place, tighten the VVT unit
securing bolt to 115 - 125 Nm.
Remove the chain tensioning tool and the wedge(s).
9. Remove the camshaft locking tool 303 - 530.
10. Raise the vehicle on the ramp.
11. Remove the crankshaft setting tool 303 - 531.

12. Refit the crankshaft position sensor.
1. Fit the sensor to the fl ywheel housing and fit the
securing bolt. Tighten to 8-12 Nm.
2. Refit the access grommet to the housing.
13. Lower the ramp.
14. Refit the A-Bank VVT Bush Carrier Assembly. Refer to
operation 12.65.51 in this Section.
15. Refit the Timing Cover. Refer to Operation 12.65.01 in this
Section.

Engine - Variable Camshaft Timing Oil Control Unit Housing LH
In-vehicle Repair
Removal
Installation
1. Open the engine compartment and fit paintwork protection
sheets.
2. Set the engine compartment cover to the service access
position.

3. Disconnect the batt ery ground cable.
Remove the battery cover.
4. Remove the Timing Co ver. Refer to Operation 12.65.01 in this
Section.

5. Remove the VVT bush carrier.
1. Remove the two bolts and one nut which secure the carrier to the cylinder block.
2. Release the carrier from the two ring dowels and
remove it.

6. Remove the seals from the bush carrier.
1. Remove the sealing ring (scarf jointed) from the
carrier bush groove.
2. Remove the O-ring from the carrier oil-way recess.
7. Clean and inspect all relevant components.
1. Fit new seals to the bush carrier.
1. Fit the new sealing ring (scarf jointed) to the carrier bush groove.
2. Fit a new O-ring to the carrier oil-way.

2. Fit the bush carrier to the cylinder block.
Lubricate the seal (scarf jointed) and the bush.
1. Fit the bush carrier assembly.
Check that the seals are in pl ace and that the ring dowels
are engaged squarely. Fully locate the assembly as much
as possible by hand pressure.
2. Fit the two securing bolts and one nut. Tighten to 19- 23 Nm.
3. Refit the Timing Cover. Refer to Operation 12.65.01 in this
Section.
4. Move the engine compartment co ver from the service position
and connect the gas struts.
5. Remove the paint protection sheets and close the cover.
6. Connect the battery and fit the battery cover.
Refer to the Battery Reconnection Procedure 86.15.15.

V
ariable Camshaft Timing Oil Control Unit Housing RH
12.65.51
Removal
1. Open the engine compartment and fit paintwork protection sheets.
2. Set the engine compartment cover to the service access position.
3
. Disconnect the battery ground cable.
Remove the battery cover.
4. Remove the Timing Cover. Refer to Operation <<12.65.01>>
in this Section.
5
. Remove the VVT bush carrier.
1. Remove the three bolts which secure the carrier to the cylinder block.

2
. Fit the bush carrier to the cylinder block.
Lubricate the seal (scarf jointed) and the bush.
1. Fit the bush carrier assembly.
 Check that the seals are in place and that the ring dowels are engaged squarely. Fully locate the
assembly as much as possible by hand pressure. 2. Fit the three securing bolts. Tighten to 19-23 Nm.
3. Refit the Timing Cover. Refer to Operation <<12.65.01>> in this Section.
4. Move the engine compartment cover from the service position and connect the gas struts.
5. Remove the paint protection sheets and close the cover.
6. Connect the battery and fit the battery cover. Refer to the Battery Reconnection Procedure <<86.15.15>>.

Th
e starter drive plate is attached to the rear of the crankshaft by eight bolts.
Timing Disc

A timing disc, for the engine speed sensor, is spot-w elded to the front face of the starter drive plate.
Starter Drive Plate

Engine Igni
tion -
Engine Ignition
Description an
d Operation
I

gnition coil and spark plug reference
Any positional r
eferences are base
d upon the following convention:
viewing from the driving position, the right-hand cylinder bank is designated bank 1 (A on circuit diagrams) and the left-
hand cylinder bank as bank 2 (B on circuit diagrams).
The cylinder bores of each bank are number ed 1 to 4, from the front of the vehicle.
Ig
nition System
Th
e ignition system provides timing cont
rol in accordance with the engine mana gement strategy and powertrain sensor
inputs; the system consists of:
engine
control module
igni

tion coils supply relay
ignit

ion control modules
igni

tion coils
spark plu

gs
Engine Control Module (ECM)
pr

ovides triggering for the ignition control modules
to control individual firing of the spark plugs
supplies ground for
the igni
tion coils supply relay
I
gnition Coils Supply Relay
The
ignition coils supply relay is located
in the engine and transmission control mo dule compartment; refer to Relay Details
in Electrical Wiring and Circuit Protection, Section 418-01.
The ECM switches a ground to the coil of the ignition coils supply relay; the relay energizes and switches a 12v supply to the
ignition control modules and the ignition coils.
I
gnition Control Modules

generates a signal when th
e dr
ive plate passes the sensor
sen
ds the ECM signals indicating crankshaft position and engine speed
is e

ssential for calculating spark timing
En

gine Coolant Temperature (ECT) Sensor
sen
ds the ECM a signal indicating the temperature of the engine coolant
is a t

emperature dependent resistor with a negative temperature coefficient (resistance changes inversely with
respect to temperature) and is constantly monitored by the ECM
Intake Air Temperature (IAT) Sensor

is m
ounted in the same housing as the MA
F sensor but is not a serviceable item
sen
ds the ECM a signal indicating the temperature of the air entering the engine
is a t

emperature dependent resistor which has a negative
temperature coefficient (its resistance changes inversely
with respect to ambient temperature).
Knock S
ensor (KS)
is a pi
ezo-electric device which sends a signal
to the ECM indicating engine detonation
Between 700 and 6800 rpm, the ECM will retard individual cylinder ignition timing when detonation occurs while allowing
the other cylinders to continue operating normally.
During acceleration, at critical load and speed conditions, the ECM retards ignition timing to prevent the onset of detonation.
H
eated Oxygen Sensor (HO2S)
are
positioned upstream of the catalytic convertor
is equipped with

a heating element wh
ich improves the response time of the sensors during engine warm-up
h
as the ability to generate a voltage signal proportional to the oxygen content of the exhaust gases leaving the
engine
pr
ovides feedback information to the ECM used to calc
ulate fuel delivery and provide optimum gas emissions
Variable V
alve Timing (VVT) Solenoid
R
efer to section 303-01.