1998 JAGUAR X308 manifold

Comp
onent Tests
Bra
k
e Booster
1.
1. Chec k all
hoses and connections. All unused vacuum connectors should be capped. Hoses and their connections
should be correctly secured and in good condition with no holes and no collapsed areas. Inspect the valve on the
brake booster for damage.
2. 2. Check the hydraulic brake system for leaks or low fluid.
3. 3. With the transmission in PARK, stop the engine and apply the parking brake. Pump the brake pedal several times
to exhaust all vacuum in the system.
4. 4. With the engine switched off and all vacuum in the system exhausted, appl y the brake pedal and hold it down.
Start the engine. If the vacuum system is operating, the brake pedal will tend to move downward under constant
foot pressure. If no motion is felt, the vacuum booster system is not functioning.
5. 5. Remove the vacuum hose from the brake booster. Manifold vacuum should be available at the brake booster end
of the hose with the engine at idle speed and the transm ission in PARK or NEUTRAL. Make sure that all unused
vacuum outlets are correctly capped, hose connectors are correctly secured and vacuum hoses are in good
condition. When it is established that manifold vacuum is available to the brake booster, connect the vacuum hose
to the brake booster and repeat Step 3. If no downward movement of the brake pedal is felt, install a new brake
booster.
6. 6. Operate the engine for a minimum of 10 seconds at a fast idle. Stop the engine and allow the vehicle to stand for
10 minutes. Then, apply th e brake pedal with approximately 89 N ( 20lb) of force. The pedal feel (brake
application) should be the same as that noted with the engine running. If the brake pedal feels hard (no power
assist), install a new valve and then re peat the test. If the brake pedal still feels hard, in stall a new brake booster.
If the brake pedal movement feels spongy, bleed the brak e system. For additional information, refer to General
Procedures in this section.
Bra k
e Master Cylinder
Usual
l
y, the first and strongest
indicator of anything wrong in the brake syst em is a feeling through the brake pedal. In
diagnosing the condition of the brake master cylinder, check pedal feel as evidence of a brake concern. Check for brake
warning lamp illumination and the brake fluid le vel in the brake master cylinder reservoir.
Normal Conditio
ns
The fo
llowing conditions are considered norm
al and are not indications that the brake master cylinder is in need of repair.
New bra
ke systems are designed to produc
e a pedal effort that is not as hard as in the past. Complaints of light
pedal efforts should be compared to the pedal effort s of another vehicle of the same model and year.
The fl
uid level will fall with brake pad wear.
Abnormal Conditions
•

NOTE: Prior to carrying out any diag
nosis, make sure the brake system warning indicator is functional.
Changes in the brake pedal feel or brake pedal travel are in dicators that something could be wrong in the brake system. The
diagnostic procedure and techniques use brake pedal feel, warning indicator illu mination and low brake fluid level as
indicators to diagnosing brake system co ncerns. The following conditions are cons idered abnormal and indicate that the
brake master cylinder is in need of repair:
Brake ped a
l goes down fast. Th
is could be caused by an ex ternal or internal leak.
Brake pedal goes down slowly
. This could be
caused by an internal or external leak.
Brak
e pedal is low or feels spongy. This condition may be ca
used by no fluid in the brake master cylinder, reservoir

Power Brake Actuation - Brake Booster
Description and Operation


The brake b
ooster provides assi
stance by reinforcing the driver's effort when brakin g. The reinforced assistance
provided by the booster is proportional to the driver's effort applied to the brake pedal.
The brake force applied by
the driver is incr
eased by the booster in a ratio of 6.5:1.
Th
e vacuum used to operate the booster
is formed in the engine's intake manifold. The booster is connected to the
intake manifold by a hose.
The boost
er is fail-safe therefore, if a fault develops in
the vacuum unit, the braking system will still function.
However, the driver will have to apply a greater fo rce to the brake pedal to slow down the vehicle.


It e
m
Par
t
Number
De
scr
iption
1—Mas
t
er Cylinder / Reservoir - refer to 206-06
2—Booster

3—Pedal Box
- refer to 206-06
4—Vacuu
m
Hose
5—No
n
-Return Valve

E
ngine Management System Components
Electronic Throt
tle
The
electronic throttle assembly, in resp
onse to signals from both the driver and the ECM, adjusts idle speed, sets the
throttle valve to the position requested by the driver's accelerator / throttle pedal, cruise and traction control, power
limitation and catalyst warm-up.
Mass
Air Flow Meter
The sensor i
s located in the air flow mete
r assembly and outputs an analogue voltag e to the ECM. This sensor measures air
flow into the engine inlet system and is calibrated to measure kg / hour.
In
take Air Temperature
Th
e intake air temperature sensor is loca
ted in the air flow meter assembly and outputs an analogue voltage to the ECM.
The ECM will substitute a default value eq ual to 50°C should this sensor fail.
Fuel Injectors
The eigh
t bottom fed fuel injectors are located in the fuel rails. Th
e fuel injectors are electromagnetic solenoid valves
controlled by the ECM. The pulse time for the injector combined with the fuel pr essure determines the volume of fuel
injected to the manifold.
Fue
l Delivery
The fu
el pump provides fuel to the fuel rail where the circulat
ing pressure is controlled by a pressure regulator valve; excess
fuel is returned to the fuel tank.
The pressure regulator valve is controlled by manifold depression so that fuel delivery pressure is maintained at
approximately 3 bar above manifold pressure.
Fuel Pump
Relay
The ECM controls thi

s component for normal
engine running. The security system may disable this relay via communication
with the ECM.
Fuel Lev
el Sensing
The tank fuel

is measured by the fuel le
vel sensor . This signal is used by the ECM as an in put to certain diagnostics.
Eva
porative Valve
Excess vapour

formed in the fuel tank is
absorbed into the evaporative emission pu rge control canister. While the engine is
running, the fuel absorbed in the canister is gradually purged back into the engine. The rate of purging is governed by
engine operating conditions and vapour concentration level. Operating conditions which affect the purge rate are:
2—Purge
valve
3—Engine

torque reduction
4—E

lectronic throttle assembly
5—Coo

ling fans
6—Ignition amplifier driver
7—Engine overspeed
8—Cli

mate control compressor clutch
9—O

BDII information (J1962, CAN, ISO)

10—F
uel pump relay
11—Heat

ed oxygen sensor
12—Vari

able valve timing
13—MIL sw

itching



ECM Out
puts
It

em
Par
t Number
De
scription
1—Exhaus

t gas recirculation

Thi
s sensor uses a piezo-electric sensing element to detect kn
ock which may occur under acceleration at critical conditions.
Should detonation be present the ECM will retard ignition timing of individual cylinders.
Exhaust G
as Recirculation
The EGR
valve (where fitted) reduces NOx
emissions by recirculating a portion of the exhaust gases back into the inlet
manifold.
Heated Oxyg
en Sensors
The h
eated oxygen sensors, one per bank, are situated upstream of the catalysts. Integral
to the sensors are heaters
(under ECM control) which allow the sensor s to reach their operating temperature as soon as possible after engine start. A
comparison between the level of oxygen in the exhaust gas to that in the atmosphere produces an output signal. This signal
is used by the engine closed loop fuel strategy to make fuelling corrections and so control overall emission levels.
Oxygen Sensors

Thes
e sensors, one per bank, are situated downstream of the
catalyst. The comparison of upstream and downstream signals
allows determination of cata lyst conversion efficiency.




Knock Sensor

Engi
ne -
Torqu
e Specifications


De
s
cription
Nmlb
-
ft
lb
-
in
A
ccessory
drive belt tensioner
43--
A
ccessory
drive belt idler pulley
61--
Air in
ta
ke tube to throttle body
5--
A/C
pipes t
o receiver / drier
9--
A/C pipe m

anifold joints
9--
Camsh

aft bearin
g caps10--
Ca
msh
aft cove
r10--
Ch
arge Air Co
oler Adaptor to cylinder head (SC)
21--
Co
olan
t outlet pipe (AJ26 NA)
10--
Cran
kshaft damper bolt - no lockin
g ring
St
ag
e 1
80--
Stag

e 2
80°--
C
r
ankshaft damper bolt - with locking ring
37
5--
Cra
nkshaft position sensor
10--
Cy
li
nder head bolts M10
35--
Cy
lin
der head bolts M8 (two at front of head)
25--
Driv
es
haft (propshaft) drive flan
ge bo
l
ts
82--
ERG p
i
pe to exhaust manifold
21--
Engi

ne compartment cover (bonnet) hinges
25--
En
gine
coolant radiator top securing panel
25--
E
ng
ine front mounting
70--
En
gine
oil cooler pipes (clamp)
21--
En
gi
ne / Transmission assembly rear mounting centre bolt
35--
En
gi
ne / Transmission assembly rear mounting outer bolts
25--
Ex
ha
ust downpipe support bracket to flywheel housing
50--
Ex
ha
ust downpipe to lower mounting bracket
48--
E
x
haust camshaft sprocket
St
age 120--
Stage 290 °--
Ex
haust manifold to cylinder head
18--
Ex
ha
ust manifold flange to downpipe
18--
E
x
haust Torca clamps
55--
Fuel cross-over elbo

w
10--
Fu
el f
eed pipe to intake manifold
10--
Fuel
Injector (AJ
26)
5--
Fuel
injector ha
rness clips to camshaft cover (SC)
5--
Fu
el p
ressure re
gu
l
ator to intake manifold
10--
F
u
el rail to Char
ge
A
ir Cooler Adaptor (SC)
21--
In
ta
ke manifold to cylinder heads
21--
Inta

ke elbow support brackets
18--
Oil f
i
lter
17--
Oil C
o
oler
7--
P
AS pu
mp hose unions
25--
P
r
imary timing chain fixed guide
12--
P
r
imary timing chain tensioner
12--
Pr

imary timing chain tensioner blade
14--
S
e
condary timing chain tensioner to cylinder
12--
S
t
eerin
g ra
ck45--
Thro
ttle body to intake elbow
21--
Th
ro
ttle cable abutment to throttle body
5--
Th
ro
ttle intake elbow to intake manifold
21--
Ti
mi
ng cover
12--
Variable camshaft t
i
ming oil control unit to intake camshaft
St
ag
e 1
20--
St
ag
e 2
90
°--
Var
iable camshaft timing oil control unit housing (bolt and nut)
21--
Va
ria
ble camshaft timi
ng oil control solenoid
12--
Wa
ter pump pulley
12--

E
ngine - Cylinder Head LH
In-ve
hicle Repair
Remova

l
CAU
TION: If a replacement cylinder head is to be installed to a
vehicle with variable camshaft timing (VCT) the cylinder head m ust have the
oil gallery blind rivet removed before installation.
Spe
cial Tool(s)

Cams

haft setting
303-530

Ti
ming chain tensioning
303-532

Wedges, prim
ary chain
303-533

Cr
ankshaft setting
303-531
1.
Open the engine compartment and install paintwork protection sheets.
2. Set the engine compartment cover to the service access position.

3.
Disconnect the battery ground cable.
Re

move the battery cover.
4. Remove the engine fron cover.For additional information, refer to: Engine
Front Cover (303-01 Engi
ne, In-vehicle Repair).
5. Remove the Inlet Manifold. Refer to Operation 30.15.01 in this Section. This operation includes depressurising the fuel system and removing the throttle
housing.
6. Disconnect the hoses and multi-plug from the coolant outlet pipe.
1. Release and reposition the hose clip, and disconnect the heater hose.
2. Disconnect the multi-plug from the temperature sensor.
3. Release and reposition the hose clip along the bypass hose.

7.
Remove the coolant outlet pipe.
1. Remove the four bolts which secure the outlet pipe.
2. Remove the outlet pipe from the bypass hose and from the cylinder heads.
8. Remove and discard the sealing ring s from the outlet pipe grooves.

9.
Remove the nuts which secure the catalytic converter to the B-Bank
exhaust manifold flange.

10 . Re
move 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.

11. R
emove 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.
12. Raise the vehicle on a ramp.
13. Remove the crankshaft position sensor.

Inst
allation
Cl
ean the gasket faces of the catalyst and the exhaust manifold.
38. Clean cylinder head and cylinder block gasket faces.
E
nsure that all threaded holes in the cylinder block face are clean and
free from oil.
Cl
ean and inspect the cylinder head bolts. They may be re-used on two
occasions. When re- used, each bolt head should be marked with one
dot from an automatic centre punch.
39. Clean and inspect all relevant components and mating faces.

1.
CAUTIONS:
If a replacement cylinder head is to be installed to a vehicle with VCT
the cylinder head must have the oil gallery blind rivet removed before
installation.
Make sure that all debris is removed from the cylinder head and cylinder
head oil gallery.
Vehicles fitted with VCT: Remove the blind rivet from the VCT oil gallary.
• NOTE: The centre bore of the blind rivet is 6 mm diameter.
I
dentify the VCT oil supply gallery and the 8 mm blind rivet.
U

sing a suitable 3 mm punch release the centre of the blind rivet until
it is released from the outer part of the blind rivet.
U
sing a suitable extraction tool, remo
ve the remaining part of the blind
rivet.
2.
Clean the component mating faces.

3.
Check cylinder head face for distortio
n, across the center and from corner
to corner.