1988 OPEL CALIBRA fuel

3Lift up the edge of the windscreen cowl
panel for access to the sensor.
4Disconnect the sensor wiring plug, and the
vacuum pipe.
5Pull the pressure sensor upwards to release
it from its bracket, and withdraw it from the
vehicle.
Refitting
6Refitting is a reversal of removal. However,
on Multec models no fuel vapour trap is fitted.
It is therefore essential that the sensor
vacuum hose is routed so that it falls steadily
from the sensor to the throttle body. This
precaution prevents any fuel droplets being
trapped in the sensor or hose, and allows
them to drain into the inlet port.
Oil temperature sensor
Removal
7The sensor is screwed into the inlet
manifold side of the cylinder block, next to the
starter motor’s right-hand end.
8The sensor can be reached quite easily
from above, but if it is to be removed from
beneath, ensure that the handbrake is
applied, and that the vehicle is securely
supported on axle stands (see “Jacking and
Vehicle Support”).
9Disconnect the battery negative lead.
10Disconnect the sensor wiring plug.
11Using a spanner, unscrew the sensor and
remove it (see illustration). Be prepared for
oil spillage, and plug the hole in the cylinder
block to prevent dirt ingress and further oil
loss.
Refitting
12Refitting is a reversal of removal.
Crankshaft speed/position
sensor (1.8 litre models)
Removal
13The sensor is located on the exhaust
manifold side of the engine, in the lower
cylinder block behind the oil pump.
14Disconnect the battery negative lead.
15Release the relevant outer timing belt
cover securing clips, and unclip the sensor
wiring from the timing belt cover.
16Disconnect the sensor wiring connector,
noting its location.
17Unscrew the securing bolt, and withdraw
the sensor from the cylinder block (see
illustration).
18Examine the sensor sealing ring, and
renew if necessary (see illustration).
Refitting
19Refitting is a reversal of removal, ensuring
that the sensor wiring is correctly located on
the timing belt cover, and that the wiring
connector is correctly located.
25Motronic system
components - removal and
refitting
3
Note: Refer to Section 3 before proceeding.
Procedures for removal and refitting of the
ignition system components and electronic
module are given elsewhere in the relevant
Sections of this Chapter. Removal and
refitting procedures for all fuel injection
system components are given in Chapter 4B
Coolant temperature sensor
Removal
1On all except 20 XEJ models, the sensor is
located in the end of the thermostat housing,
on the inlet manifold side of the engine.
2On 20 XEJ models, the sensor is located in
the thermostat housing, on the exhaust
manifold side of the engine.
3Disconnect the battery negative lead.
4Partially drain the cooling system, as
described in Chapter 3. 5Disconnect the sensor wiring plug (see
illustration).
6Using a spanner, unscrew the sensor and
withdraw it from the thermostat housing.
Refitting
7Refitting is a reversal of removal.
8On completion, top-up the cooling system,
as described in Chapter 3.
Knock sensor (DOHC models)
Removal
9The sensor is located at the lower inlet
manifold side of the cylinder block, below the
idle speed adjuster, and is only accessible
from below the vehicle.
10Disconnect the battery negative lead.
11Apply the handbrake, then jack up the
front of the vehicle, and support securely on
axle stands (see “Jacking and Vehicle
Support”) placed under the body side
members.
12Remove the engine undershield, as
described in Chapter 11.
13Disconnect the sensor wiring plug.
14Unscrew the securing bolt, and withdraw
the sensor from the cylinder block.
Refitting
15Refitting is a reversal of removal, but note
that the mating faces of the sensor and
cylinder block must be cleaned thoroughly
before fitting the sensor.
Engine electrical systems 5•15
24.17 Unscrewing the crankshaft
speed/position sensor securing bolt -
1.8 litre model
25.5 Disconnecting the coolant
temperature sensor wiring plug - 2.0 litre
model (alternator removed)24.18 Examine the crankshaft
speed/position sensor sealing ring -
1.8 litre model
24.11 Unscrewing the MSTS-i oil
temperature sensor - 1.6 litre model
(engine removed)24.1 MSTS-i manifold pressure sensor -
1.6 litre model
5

11
Torque wrench settingNm lbf ft
Front seat rails to floor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Seat belt fixings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 26
1 General description
The bodyshell and floorpan are of pressed
steel, and form an integral part of the vehicle’s
structure, without the need for a separate
chassis.
Various areas are strengthened, to provide
for suspension, steering and engine mounting
points, and load distribution.
Extensive corrosion protection is applied to
all new vehicles. Various anti-corrosion
preparations are used, including galvanising
and PVC under-sealing. Protective wax is
injected into the box sections and other
hollow cavities.
Extensive use is made of plastic for
peripheral components, such as the radiator
grille, bumpers and wheel trims, and for much
of the interior trim.Interior fittings are to a high standard on all
models, and a wide range of optional
equipment is available throughout the range.
Except for the rear quarter windows, all
fixed glass is bonded in position, using a
special adhesive. Any work in this area should
be entrusted to a Vauxhall dealer or glass
replacement specialist.
2 Bodywork and underframe -
maintenance
1
The general condition of a vehicle’s
bodywork is the one thing that significantly
affects its value. Maintenance is easy but
needs to be regular. Neglect, particularly after
minor damage, can lead quickly to further
deterioration and costly repair bills. It is
important also to keep watch on those partsof the vehicle not immediately visible, for
instance the underside, inside all the wheel
arches and the lower part of the engine
compartment.
The basic maintenance routine for the
bodywork is washing preferably with a lot of
water, from a hose. This will remove all the
loose solids that may have stuck to the
vehicle. It is important to flush these off in
such a way as to prevent grit from scratching
the finish. The wheel arches and underframe
need washing in the same way to remove any
accumulated mud that will retain moisture and
tend to encourage rust. Oddly enough, the
best time to clean the underframe and wheel
arches is in wet weather when the mud is
thoroughly wet and soft. In very wet weather
the underframe is usually cleaned of large
accumulations automatically and this is a
good time for inspection.
Periodically, except on vehicles with a
Chapter 11
Bodywork and fittings
Bodywork and underframe - maintenance . . . . . . . . . . . . . . . . . . . . . .2
Bonnet - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Bonnet lock components - removal and refitting . . . . . . . . . . . . . . . . .7
Bonnet lock release cable - removal and refitting . . . . . . . . . . . . . . . .8
Boot lid (Saloon models) - removal and refitting . . . . . . . . . . . . . . . . .9
Boot lid lock (Saloon models) - removal and refitting . . . . . . . . . . . . .10
Boot lid lock cylinder (Saloon models) - removal and refitting . . . . . .11
Bumpers - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Centre console - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . .38
Door - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
Door check arm - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .22
Door exterior handle - removal and refitting . . . . . . . . . . . . . . . . . . . .19
Door inner trim panel - removal and refitting . . . . . . . . . . . . . . . . . . .17
Door interior handle - removal and refitting . . . . . . . . . . . . . . . . . . . .18
Door lock - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Door lock barrel - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .20
Door mirror - removal, overhaul and refitting . . . . . . . . . . . . . . . . . . .27
Door window - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .25
Door window regulator - removal and refitting . . . . . . . . . . . . . . . . . .26
Engine undershield (DOHC models) - removal and refitting . . . . . . . .32
Facia panels - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . .37
Fuel filler flap - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .33General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Headlining - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Interior trim panels - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Interior trim panels - removal and refitting . . . . . . . . . . . . . . . . . . . . .36
Major body damage - repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Minor body damage - repair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Radiator grille panel - removal and refitting . . . . . . . . . . . . . . . . . . . .29
Rear quarter windows - removal and refitting . . . . . . . . . . . . . . . . . .24
Seat belts - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
Seat belt tensioners - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42
Seats (without tensioners) - removal and refitting . . . . . . . . . . . . . . .40
Seats, front (with seat belt tensioners) - removal and refitting . . . . . .43
Sunroof - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Tailgate (Hatchback models) - removal and refitting . . . . . . . . . . . . .12
Tailgate lock (Hatchback models) - removal and refitting . . . . . . . . .13
Tailgate lock cylinder (Hatchback models) - removal and refitting . .14
Tailgate strut (Hatchback models) - removal and refitting . . . . . . . . .15
Upholstery and carpets - maintenance . . . . . . . . . . . . . . . . . . . . . . . .3
Wheel arch liners - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Windscreen and rear window - removal and refitting . . . . . . . . . . . . .23
Windscreen cowl panel - removal and refitting . . . . . . . . . . . . . . . . .30
11•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321

4Certain models may have additional
underbody shields and splashguards fitted,
which may be attached to the wheel arch liners.
32Engine undershield (DOHC
models) - removal and
refitting
2
Removal
1Apply the handbrake, then jack up the front
of the vehicle, and support on axle stands
(see “Jacking and Vehicle Support”).
2Extract the two securing screws, and
remove the oil filter access panel.
3Working around the edges of the splash
shield, remove the self tapping screws that
secure the shield to the body, noting that
some of the screws also secure the wheel
arch liners.
4With the help of an assistant, pull the shield
from the vehicle, and place it to one side to
avoid damage.
Refitting
5Refitting is a reversal of removal.
33Fuel filler flap -removal and
refitting
2
Removal
1Open the flap for access to the four screws
securing the flap to the rear wing.2Remove the securing screws, and withdraw
the flap.
Refitting
3Refitting is a reversal of removal.
34Sunroof components -
removal and refitting
4
Note:The sunroof is a complex piece of
equipment consisting of a large number of
components. It is strongly recommended that
the sunroof mechanism is not disturbed unless
necessary. If the sunroof mechanism is faulty, or
requires overhaul, consult a dealer for advice.
Glass panel
Removal
1Push the sunshade fully rearwards, and
open the glass panel halfway.
2Extract the four securing screws from the
front edge of the guide rail plastic surround,
and withdraw the surround down through the
sunroof aperture (see illustrations).
3Move the glass panel forward, and open it
to its tilt position.
4Prise the plastic trim strips from the guide
rails, to expose the glass panel securing
screws (see illustration).5Extract the three securing screws from
each guide rail, and where applicable, recover
the lockwashers (see illustration).
6Carefully lift the glass panel from the roof
aperture, taking care not to damage the
vehicle paintwork (see illustration).
Refitting
7Refitting is a reversal of removal,
remembering the following points.
8Before refitting the glass panel, measure
the distance between the mounting flanges.
Bend the flanges if necessary to achieve the
desired dimension (see illustration).
Bodywork and fittings 11•13
34.4 Prising a plastic trim strip from the
guide rail
34.6 Lifting the glass panel from the roof
aperture
34.5 Loosening a glass panel securing
screw
34.2B . . . and withdraw the guide rail
plastic surround34.2A Extract the four securing screws . . .
11
34.8 Sunroof glass panel mounting
flange dimension
1 Mounting flange
2 Nut
3 Protective foil
A-A Cross-section cutting point
(Dimensions in mm)

4C
Torque wrench settingsNm lbf ft
AIR non-return valve to pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
AIR pipe support bracket to manifold . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
AIR pipe to manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
AIR pipe to support bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
AIR pump bracket to protective shield . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
AIR pump to wheel arch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
AIR pump to insulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
AIR valves to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3
Carbon canister . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3
EGR valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 15
Heat shield . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Oxygen sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 22
Chapter 4 Part C:
Fuel and exhaust systems - exhaust and emissions
AIR cut-off valve - removal, testing and refitting . . . . . . . . . . . . . . . . .7
AIR pipe and non-return valve - removal and refitting . . . . . . . . . . . . .9
AIR pump assembly (Simtec system) - removal and refitting . . . . . . . .6
AIR switchover valve - removal and refitting . . . . . . . . . . . . . . . . . . . .8
Carbon canister - removal and refitting . . . . . . . . . . . . . . . . . . . . . . .11
Catalytic converter - description, general and precautions . . . . . . . .10
EGR module (X 16 SZ models) - removal and refitting . . . . . . . . . . . . .5EGR valve (Multec system models) - testing, removal and refitting . . .3
EGR valve (Simtec system) - testing, removal and refitting . . . . . . . . .4
Emissions control systems - general . . . . . . . . . . . . . . . . . . . . . . . . . .1
Exhaust gas recirculation (EGR) system - general . . . . . . . . . . . . . . . .2
Exhaust manifold - removal and refitting . . . . . . . . . . . . . . . . . . . . . .13
Exhaust system - checking, removal and refitting . . . . . . . . . . . . . . .14
Oxygen sensor (catalytic converter models) - removal and refitting .12
4C•1
Specifications Contents
1 Emissions control systems -
general
General
Multec system
1An evaporative emissions control system is
fitted to minimise the escape into the
atmosphere of unburned hydrocarbons.
2The fuel tank filler cap is sealed and a
charcoal canister is mounted under the
right-hand front wing to collect the petrol
vapours generated in the tank when the
vehicle is parked. It stores them until they can
be purged from the canister into the inlet tract
to be burned by the engine during normal
combustion. The canister’s control valve (on
the top of the canister) is opened by a vacuum
pipe from the front of the throttle body on C16
NZ, C16 NZ2 and C18 NZ engines. On X16 SZ
it’s opened by an electronically activated
purge valve, mounted on the camshaft
housing.
Motronic system
3The system is as described in Chapter 4B,
except that the charcoal canister is purged
under the control of the fuel injection/ignition
system module through the fuel tank vent
valve. To ensure that the engine runs correctly
when it is cold and/or idling, and to protect
the catalytic converter from the effects of an
over-rich mixture, the valve is not opened by
the module until the engine is under partial or
full load. The valve solenoid is then modulated
on and off to allow the stored vapour to pass
into the inlet tract.
4Canister removal and refitting is as
described in Section 11.
5On C20 NE engines, the vent valve is
mounted above the injectors for cylinders 2
and 4. To remove it, disconnect the battery
negative lead and the valve wiring plug, then
disconnect the two vent hoses having made
note of their connections. Either remove the
valve from its mounting bracket, or unbolt the
bracket, as required.
6On C20 XE engines, the vent valve is
mounted on the left-hand end of the engine,underneath the end of the fuel injector wiring
harness housing (see illustration). Removal
and refitting is as described in the previous
paragraph.
Simtec system
7For information refer to “General
description”, in Chapter 4B. Note that “AIR”,
is an abbreviation for the secondary Air
Injection Reactor system used on this model.
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321
1.6 Disconnecting the fuel tank vent valve
wiring

2Exhaust gas recirculation
(EGR) system - general
The system reintroduces small amounts of
exhaust gas into the combustion cycle to
reduce the generation of oxides of nitrogen
(NOx).
On C16 NZ, C16 NZ2 and C18 NZ engines,
the volume of exhaust gas reintroduced is
governed by manifold vacuum, through the
EGR valve mounted on the inlet manifold.
When the valve is opened small amounts of
exhaust gas are allowed to enter the inlet
tract, passing through ports in the cylinder
head.
On X16 SZ engines the EGR valve is
operated by an EGR module, mounted on the
left-hand side of the engine compartment
behind the battery. This module amplifies
signals received from the fuel system ECU
and operates the EGR valve electronically
providing precise control of exhaust gas
recirculation under all engine conditions.
3EGR valve (Multec system
models) - testing, removal and
refitting
2
Testing
1On C16 NZ, C16 NZ2 and C18 NZ engines,
it is recommended that the system is checked
annually, by checking the movement of the
valve’s diaphragm carrier plate as follows.
Note that the carrier plate is visible only
through the apertures in the underside of the
valve, so a battery-operated torch and small
mirror may be useful. On X16 SZ engines,
Vauxhall test equipment is necessary to check
the EGR system.
2With the engine fully warmed up to normal
operating temperature and idling, briefly open
and close the throttle. The carrier plate should
move upwards as the manifold vacuum
changes. When the engine is idling smoothly
again, press the carrier plate upwards (do this
very carefully, so that the plate is not distorted or
the diaphragm damaged). The idle speed should
drop significantly (approximately 100 rpm).
3If the valve does not respond as described,
it must be cleaned.
Removal
4Pull off the hose from the valve, then unbolt
the valve and remove it (see illustrations).
Clean away all carbon using a wire brush and
a pointed tool, but take care not to damage
the valve seat. Renew the valve gasket to
prevent induction leaks.
Refitting
5Refit the valve and reconnect the hose,
then recheck the system’s performance; if
there is no improvement, the valve must be
renewed.
4EGR valve (Simtec system) -
testing, removal and refitting
3
Note: A new gasket will be required when
refitting the valve.
Removal
1Disconnect the battery negative lead.
2Remove wiring harness and vacuum hose.
3Mark position of the valve, to ensure
correct relocation.
4Undo the 3 bolts, and remove the valve
from the dual spark ignition coil’s coolant
flange.
Refitting
5Clean the sealing surfaces of the valve and
flange.
6Refit the valve with a new gasket and line
up the marks made before removal (see
illustration).
5EGR module (X16 SZ
models) - removal and
refitting
2
Removal
1Disconnect the knock module from its
bracket (refer to Chapter 4B, if necessary),
and place to one side.
2Remove wiring plug from module. Remove
module from bracket.
Refitting
3Refitting is a reversal of removal.
6AIR pump assembly (Simtec
system) - removal and refitting
3
Removal
1Chock the rear wheels, jack up the front of
the vehicle and support it on axle stands
placed under the body side members (see
“Jacking and Vehicle Support”)
2Remove the left hand front wheel and inner
wheel arch lining.
3Loosen the hose clamp and remove the air
duct hose from the pump.
4Disconnect the battery negative lead.
5Undo the securing nuts and remove the
pump assembly from its location. Disconnect
the wiring plug.
6Remove the wiring plug from the pump’s
bracket.
7Mark the position of the pump on it’s
bracket before separating.
8Remove the fixing bolts and disconnect the
pump from it’s insulator.
9The insulator can also be checked by
removing the 3 nuts, securing the protective
shield. Before removing, mark the shield and
insulator. Replace if necessary.
10Check the pump’s air cleaner for damage.
Refitting
11Refitting is a reversal of removal. Ensure
correct alignment of the components.
7AIR cut-off valve - removal,
testing and refitting
3
Removal
1Before removal, mark on the cut-off valve,
the direction of flow towards the non-return
valve (see illustration).
2Disconnect and remove the air duct and
vacuum hoses.
3Undo the switchover valve’s bolts and
move to one side.
4C•2Fuel and exhaust systems - exhaust and emissions
3.4 Disconnecting the vacuum hose from
the exhaust gas recirculation valve
4.6 EGR valve
1 Valve 2 Gasket
3.4B Withdrawing the exhaust gas
recirculation valve

4The cut-off valve can now be removed from
the bracket.
Testing
5To test the cut-off valve a vacuum hand
pump with gauge will be required. If available,
connect to the cut-off valve and ensure that
air through-flow aperture is fully open.
Refitting
6Refitting is a reversal of removal. Ensure
valve is fitted in the correct direction.
8AIR switchover valve -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Disconnect wiring plug from the valve.
3Mark the location of the vacuum hoses
before removing them from the valve.
4After disconnecting the hoses undo the two
bolts, and remove them from its bracket.
Refitting
5Refitting is a reversal of removal. Ensure
hoses are fitted correctly (see illustration).
9AIR pipe and non-return
valve - removal and refitting
3
Note:New air pipe washers will be required
when refitting.
Removal
1Remove the non-return valve air duct hose.
2Undo the bolts engine lifting eye bracket,
and turn the bracket on to its left hand side.
3Remove the pipe support bracket by
releasing its three bolts.
4Remove the heat shield that is secured by
two bolts.
5The air pipe can now be removed by
releasing the two securing bolts.
6If necessary the non-return valve can now
be disconnected.
7Carefully clamp the pipe using a vice with
protective jaws. Unbolt the valve from the
pipe, clean and inspect for damage.
Refitting
8Before refitting, coat the threads of the non-
return valve with sealing compound (i.e.
Vauxhall part no. 90094714).
9Use new washers when refitting the pipe,
(take care as the washers have sharp edges).
Coat the pipe mounting bolts with assembly
paste (i.e. Vauxhall part no. 90513210), before
refitting.
10Refitting is a reversal of removal.
Retighten to correct torque as shown in Spec-
ifications.
10Catalytic converter -
description, general and
precautions
Note: The catalytic converter is not a filter. It
creates a chemical reaction, but it is not
affected by that reaction.
Description
1Certain models are available with a catalytic
converter, to reduce exhaust emissions.
These models can be identified by a ‘C’ or ‘X’,
prefixing the engine code.
2The purpose of the catalytic converter is to
change potentially harmful hydrocarbon andcarbon monoxide exhaust gases into harmless
gases and water vapour. The converter
consists of a stainless steel canister containing
a catalyst-coated honeycomb ceramic. The
catalyst is a mixture of three precious metals,
platinum, palladium and rhodium.
3The exhaust gases pass freely through the
honeycomb, where the catalyst speeds up the
chemical change of the exhaust gases,
without being permanently altered itself.
4To avoid damage to the catalyst, the engine
must be kept properly tuned, and unleaded
petrol must always be used. Normal leaded
petrol will “poison” the catalyst, and must not
be used.
5To enable the Motronic engine management
system to achieve complete combustion of the
fuel mixture, and thus to minimise exhaust
emissions, an oxygen sensor is fitted in the
exhaust gas stream. The sensor monitors the
oxygen level in the exhaust gas, and sends a
signal to the Motronic module. The module
constantly alters the fuel/air mixture within a
narrow band to reduce emissions, and to allow
the catalytic converter to operate at maximum
efficiency. No adjustment of idle mixture is
therefore possible on models fitted with a
catalytic converter.
General
6Ninety-nine per cent of exhaust gases, from
a petrol engine (however efficient or well
tuned), consists of nitrogen (N
2), carbon
dioxide (CO
2), oxygen (O2), other inert gases
and water vapour (H
2O). The remaining 1% is
made up of the noxious materials that are
currently seen (except CO
2), as the major
polluters of the environment. Carbon
monoxide (CO), unburned hydrocarbons (HC),
oxides of nitrogen (NOx) and some solid
matter, including a small lead content.
7The device most commonly used to clean
up vehicle exhausts is the catalytic converter.
It is fitted into the vehicle’s exhaust system
and uses precious metals (platinum and
palladium or rhodium) as catalysts to speed
up the reaction between the pollutants and
the oxygen in the exhaust gases. CO and HC
being oxidised to form H
2O and CO2and (in
the three-way type of catalytic converter) NOx
being reduced to N
2.
8The converter consists of an element of
ceramic honeycomb, coated with a
combination of precious metals in such a way
as to produce a vast surface area over which
the exhaust gases must flow. The three-way
closed-loop type converter fitted to these
models can remove over 90% of pollutants.
9The catalytic converter is a reliable and
simple device that needs no maintenance.
However there are some facts that an owner
should be aware if the converter is to function
properly for its full service life (see
illustration).
a)DO NOT use leaded petrol in a vehicle
equipped with a catalytic converter. The
lead will coat the precious metals,
reducing their converting efficiency and
will eventually destroy the converter.
Fuel and exhaust systems - exhaust and emissions 4C•3
10.9 The catalytic converter is protected
by heat shields
8.5 AIR switchover valve
1 Connection to brake servo vacuum hose
2 Connection to cut-off valve
7.1 AIR cut-off valve
1 Connection to AIR pump
2 Connection to AIR switchover valve
3 Connection to AIR non-return valve
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b)Always keep the ignition and fuel systems
well maintained according to the
manufacturers schedule (see “Routine
maintenance” and the relevant Chapter).
In particular, ensure that the air cleaner
filter element, the fuel filter and the spark
plugs are renewed at the correct intervals.
If the inlet air/fuel mixture is allowed to
become too rich due to neglect, the
unburned surplus will enter and burn in
the catalytic converter, overheating the
element and eventually destroying the
converter.
c)If the engine develops a misfire, do not
drive the vehicle at all (or at least as little
as possible) until the fault is cured. The
misfire will allow unburned fuel to enter
the converter, which will result in its
overheating, as noted above.
d)The engine control indicator (the outline
of an engine with a lightning symbol
superimposed), will light when the ignition
is switched on and the engine is started,
then it will go out. While it may light briefly
while the engine is running, it should go
out again immediately and stays unlit. If it
lights and stays on while the engine is
running, seek the advice of a Vauxhall
dealer as soon as possible. A fault has
occurred in the fuel injection/ignition
system that, apart from increasing fuel
consumption and impairing the engine’s
performance, may damage the catalytic
converter.
e)DO NOT push or tow-start the vehicle.
This will soak the catalytic converter in
unburned fuel causing it to overheat when
the engine does start see (b) above.
f)DO NOT switch off the ignition at high
engine speeds. If the ignition is switched
off at anything above idle speed,
unburned fuel will enter the (very hot)
catalytic converter, with the possible risk
of its igniting on the element and
damaging the converter.
g)DO NOT use fuel or engine oil additives.
These may contain substances harmful to
the catalytic converter.
h)DO NOT continue to use the vehicle if the
engine burns oil to the extent of leaving a
visible trail of blue smoke. The unburned
carbon deposits will clog the converter
passages and reduce its efficiency; in
severe cases the element will overheat.
i)Remember that the catalytic converter
operates at very high temperatures hence
the heat shields on the vehicle’s under-
body and the casing will become hot
enough to ignite combustible materials
that brush against it. DO NOT, therefore,
park the vehicle in dry undergrowth, over
long grass or over piles of dead leaves.
j)Remember that the catalytic converter is
FRAGlLE. Do not strike it with tools during
servicing work. Take great care when
working on the exhaust system. Ensure
that the converter is well clear of any
jacks or other lifting gear used to raise thevehicle. Do not drive the vehicle over
rough ground, road humps, etc., in such a
way as to ground the exhaust system.
k)In some cases, particularly when the
vehicle is new and/or is used for
stop/start driving, a sulphurous smell (like
that of rotten eggs) may be noticed from
the exhaust. This is common to many
catalytic converter-equipped vehicles and
seems to be due to the small amount of
sulphur found in some petrol’s reacting
with hydrogen in the exhaust to produce
hydrogen sulphide (CS) gas. While this
gas is toxic, it is not produced in sufficient
amounts to be a problem. Once the
vehicle has covered a few thousand miles
the problem should disappear. In the
meanwhile a change of driving style or of
the brand of petrol may effect a solution.
l)The catalytic converter, used on a
well-maintained and well-driven vehicle,
should last for between 50 000 and 100
000 miles. From this point on, careful
checks should be made at all specified
service intervals of the CO level to ensure
that the converter is still operating
efficiently. If the converter is no longer
effective it must be renewed.
11Carbon canister - removal
and refitting
3
Removal
1Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members
(see “Jacking and Vehicle Support”).
2Remove the front right hand wheel and
wheel arch liner.
3Note the hose and pipe connections to the
canister, or label them, to ensure that they are
reconnected to their original unions, then
disconnect them (see illustration). Unscrew
the two nuts securing the canister mounting
bracket to the vehicle body.
Refitting
4Refitting is a reversal of removal, however
ensure correct fitment of hose and pipes.
12Oxygen sensor (catalytic
converter models) - removal
and refitting
3
Note: This sensor is also known as a Lambda
sensor.
Removal
1Disconnect the battery negative lead.
2Disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
3Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands placed under the body side members.
4On DOHC models, remove the engine
undershield, as described in Chapter 11.
5On models fitted with Multec injection
system, the sensor is screwed into the
exhaust manifold. Trace the wiring from the
sensor itself to the connector (either clipped
to the radiator cooling fan shroud or behind
the coolant expansion tank). Release it from
any clips or ties; disconnect the wiring before
unscrewing the sensor.
6On other models, unscrew the oxygen
sensor from the front section of the exhaust
system (see illustration). It is advisable to
wear gloves, as the exhaust system will be
extremely hot.
7Withdraw the oxygen sensor and its wiring,
taking care not to burn the wiring on the
exhaust system. If the sensor is to be re-used,
take care that the sealing ring is not lost, and
that the sensor is not dropped.
Refitting
8If a new sensor is being fitted, it will be
supplied with the threads coated in a special
grease to prevent it seizing in the exhaust
system.
9If the original sensor is being refitted,
ensure that the screw thread is clean. Coat
the thread with a lithium based copper grease
(i.e. Vauxhall Part No. 90295397).
10Refitting is a reversal of removal. Check
the exhaust system for leakage when the
engine is re-started.
4C•4Fuel and exhaust systems - exhaust and emissions
12.6 Oxygen sensor location in front
section of exhaust system - DOHC models
11.3 Charcoal canister
A Vent to atmosphere
B Vapour feed hose from filler pipe
C Vapour exhaust hose to inlet tract
D Control valve vacuum pipe from
throttle body

13Exhaust manifold - removal
and refitting
3
Note:New manifold-to-cylinder head, and
manifold-to-downpipe, gaskets must be used
on refitting. Exhaust manifolds on DOHC
models are of tubular design, which form part
of the front section of the exhaust.
Removal
1Disconnect the battery negative lead.
2Disconnect the HT leads from the spark
plugs, if necessary labelling them to ensure
refitting to the correct cylinders.
3Loosen the clamp screw and disconnect
the air cleaner hot air tube from the shroud on
the manifold, if fitted. Remove the securing
screws and withdraw the hot air shroud from
the manifold.
4Working under the manifold, unscrew and
remove the four bolts securing the exhaust
downpipe to the manifold.
5If fitted, disconnect the oxygen sensor
wiring
6Separate the downpipe from the manifold,
and support with wire or string. Do not allow
the front section of the exhaust system to hang
under its own weight. Recover the gasket.
7Unscrew the securing nuts, and withdraw
the manifold from the cylinder head (see
illustration). Recover the gasket.
8It is possible that some of the manifold
studs may be unscrewed from the cylinder
head when the manifold securing nuts are
unscrewed. In this event, the studs should be
screwed back into the cylinder head once the
manifold has been removed, using two
manifold nuts locked together.
Refitting
9Refit the manifold using a new gasket, and
tighten the securing nuts to the specified
torque.
10Reconnect the exhaust downpipe to the
manifold, using a new gasket and tighten the
securing bolts to the specified torque.
11Further refitting is a reversal of removal.
14Exhaust system - checking,
removal and refitting
2
Note: All relevant gaskets and/or sealing rings
should be renewed on refitting
Checking
1Periodically, the exhaust system should be
checked for signs of leaks or damage. Also
inspect the exhaust system rubber
mountings, and renew if necessary.
2Small holes or cracks can be repaired using
proprietary exhaust repair products, but
where more serious corrosion or damage is
evident, renewal will be necessary.
Removal
3The original factory-fitted exhaust system
consists of four separate sections, all of which
can be renewed individually.
4On models fitted with a catalytic converter,
an oxygen sensor is fitted to the front section
of the exhaust. The catalytic converter is fitted
in place of the front expansion box in the
conventional exhaust system. The
manufacturers do not specify any renewal
intervals for the catalytic converter.
5Before renewing an individual section of the
exhaust system, it is wise to inspect the
remaining sections. If corrosion or damage is
evident on more than one section of the
system, it may prove more economical to
renew the entire system.
6Individual sections of the exhaust system
can be removed as follows.
Front section - SOHC models
7On models with a catalytic converter,
disconnect the battery negative lead, and
disconnect the oxygen sensor wiring plug,
which is located behind the coolant expansion
tank.
8Raise the vehicle, and support securely on
axle stands placed under the body side
members (see “Jacking and Vehicle
Support”).
9Unscrew the two securing bolts, and
disconnect the exhaust front section from the
front expansion box or catalytic converter (as
applicable) at the flexible joint. Recover the
sealing ring and the springs (see illustration).10Unbolt the exhaust front section from the
bracket on the cylinder block (see
illustration).
11Unscrew and remove the four bolts
securing the downpipe to the exhaust
manifold, and withdraw the exhaust front
section (see illustration). Recover the
downpipe-to-manifold gasket.
Refitting
12Refitting is a reversal of removal, but use a
new gasket when reconnecting the downpipe
to the manifold, and a new sealing ring when
connecting the flexible joint. Tighten all fixings
to the specified torque.
Front section - DOHC models
Removal
13Proceed as described in paragraphs 7
and 8.
14Remove the engine undershield, as
described in Chapter 11.
15Proceed as described in paragraphs 9
and 10.
16Working in the engine compartment,
remove the bolts securing the exhaust
manifold heat shield to the cylinder head.
17Unscrew the two lower exhaust manifold
securing nuts that also secure the heat shield
brackets, and withdraw the heat shield (see
illustration).
18Unscrew the remaining manifold securing
nuts, then withdraw the manifold/exhaust
front section from the vehicle. Recover the
manifold gasket.
Fuel and exhaust systems - exhaust and emissions 4C•5
14.10 Exhaust front section support
bracket - SOHC models
14.11 Unscrewing a downpipe-to-exhaust
manifold bolt - SOHC models
14.9 Exhaust front section flexible joint -
SOHC models13.7 Unscrewing an exhaust manifold
securing nut - SOHC models
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