1988 OPEL CALIBRA oil temperature

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

4B
cruising and accelerating. The injector earth is
also switched off on the overrun to improve
fuel economy and reduce exhaust emissions.
Additionally, on the X16 SZ engine, the ECU
also controls the operation of the charcoal
canister purge valve in the evaporative
emission control system.
10The oxygen sensor screwed into the
exhaust manifold provides the ECU with a
constant feedback signal. This enables it to
adjust the mixture (closed-loop control) to
provide the best possible conditions for the
catalytic converter to operate effectively.
11Until the oxygen sensor is fully warmed up
it gives no feedback so the ECU uses
pre-programmed values (open-loop control) to
determine the correct injector pulse width.
When the sensor reaches its normal operating
temperature, its tip (which is sensitive to
oxygen) sends the ECU a varying voltage
depending on the amount of oxygen in the
exhaust gases. If the inlet air/fuel mixture is too
rich, the exhaust gases are low in oxygen so the
sensor sends a low-voltage signal. The voltage
rises as the mixture weakens and the amount of
oxygen rises in the exhaust gases. Peak
conversion efficiency of all major pollutants
occurs if the inlet air/fuel mixture is maintained
at the chemically correct ratio for the complete
combustion of petrol of 14.7 parts (by weight) of
air to 1 part of fuel (the “stoichiometric” ratio).
The sensor output voltage alters in a large step
at this point, the ECU using the signal change
as a reference point and correcting the inlet
air/fuel mixture accordingly by altering the fuel
injector pulse width.
12In addition, the ECU senses battery
voltage, incorporates diagnostic capabilities,
and can both receive and transmit information
by way of the diagnostic connector, thus
permitting engine diagnosis and tuning by
Vauxhall’s TECH1, test equipment.
Motronic system
13The Motronic type is available in several
different versions, depending on model. The
system is under the overall control of the
Motronic engine management system (Chapter
5), which also controls the ignition timing.
14Fuel is supplied from the rear-mounted
fuel tank by an electric fuel pump mounted
under the rear of the vehicle, through a
pressure regulator, to the fuel rail. The fuel rail
acts as a reservoir for the four fuel injectors,
which inject fuel into the cylinder inlet tracts,
upstream of the inlet valves. On SOHC
engines, the fuel injectors receive an electrical
pulse once per crankshaft revolution, which
operates all four injectors simultaneously. On
DOHC engines, sequential fuel injection is
used, whereby each injector receives an
individual electrical pulse allowing the four
injectors to operate independently, which
enables finer control of the fuel supply to each
cylinder. The duration of the electrical pulse
determines the quantity of fuel-injected, and
pulse duration is computed by the Motronic
module, based on the information received
from the various sensors.15On SOHC engines, inlet air passes from
the air cleaner through a vane type airflow
meter, before passing to the cylinder inlet
tracts through the throttle valve. A flap in the
vane airflow meter is deflected in proportion
to the airflow; this deflection is converted into
an electrical signal, and passed to the
Motronic module. A potentiometer screw
located on the airflow meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
16On DOHC engines, inlet air passes from
the air cleaner through a hot wire type air
mass meter, before passing to the cylinder
inlet tracts through a two-stage throttle body
assembly. The electrical current required to
maintain the temperature of the hot wire in the
air mass meter is directly proportional to the
mass flow rate of the air trying to cool it. The
current is converted into a signal, which is
passed to the Motronic module. The throttle
body contains two throttle valves that open
progressively, allowing high torque at part
throttle, and full-throttle, high-speed
“breathing” capacity. A potentiometer screw
located on the air mass meter provides the
means of idle mixture adjustment, by altering
the reference voltage supplied to the Motronic
module.
17A throttle position sensor enables the
Motronic module to compute the throttle
position, and on certain models, its rate of
change. Extra fuel can thus be provided for
acceleration when the throttle is opened
suddenly. Information from the throttle
position sensor is also used to cut off the fuel
supply on the overrun, thus improving fuel
economy and reducing exhaust gas
emissions.
18Idle speed is controlled by a variable-
orifice solenoid valve, which regulates the
amount of air bypassing the throttle valve. The
valve is controlled by the Motronic module;
there is no provision for direct adjustment of
the idle speed.
19Additional sensors inform the Motronic
module of engine coolant temperature, air
temperature, and on models fitted with a
catalytic converter, exhaust gas oxygen
content.
20A fuel filter is incorporated in the fuel
supply line, to ensure that the fuel supplied to
the injectors is clean.
21A fuel pump cut-off relay is controlled by
the Motronic module, which cuts the power to
the fuel pump should the engine stop with the
ignition switched on, if there is an accident. All
1993-onwards models equipped with
Motronic systems, have their fuel pump
located inside the fuel tank.
22The later M2.8 system is basically the
same as the earlier M2.5 system apart from
the following:
a)Hot Film Mass Airflow Meter - The hot
wire type unit used previously is replaced
on the M2.8 system by a hot film mass
airflow meter. The operation is the sameexcept that a thin, electrically heated plate
rather than a wire is used. The plate is
maintained at a constant temperature by
electric current as the inlet air mass
passing over the plate tries to cool it. The
current required to maintain the
temperature of the plate is directly
proportional to the mass flow rate of the
inlet air. The current is converted to a
signal that is passed to the Motronic
module.
b)Inlet Air Temperature Sensor -The sensor
is located in the hose between the hot
film mass airflow meter and the air cleaner
for precise monitoring of inlet air
temperature. Signals from the sensor are
used in conjunction with other sensors to
indicate the occurrence of a hot start
condition. The Motronic module then
interprets these signals to alter injector
duration accordingly.
c)Throttle Valve Potentiometer -On the
M2.8 system a throttle valve
potentiometer replaces the throttle valve
switch used previously.
Simtec system
23An increased amount of electronic
components are used instead of mechanical
parts as sensors and actuators with the
Simtec engine management system. This
provides more precise operating data as well
as greater problem free motoring.
24The control unit is equipped with
electronic ignition control. Called ‘Micropro-
cessor Spark Timing System, inductive
triggered’, (or MSTS-i), and means that the
mechanical high voltage distributor is no
longer needed. It is located behind the trim
panel, on the right-hand side footwell (door
pillar).
25The ignition coil is replaced by a dual
spark ignition coil, which is switched directly
by the output stages in the control unit.
26A camshaft sensor will maintain
emergency operation, should the crankshaft
inductive pulse pick-up, malfunction. These
sense TDC (‘Top Dead Centre’), crankshaft
angle and engine speed. The signals are used
by the control unit to calculate ignition point
and for fuel injection.
27The ‘hot film airflow meter’ determines the
mass of air taken in by the engine. The system
uses this information to calculate the correct
amount of fuel needed for injection in the
engine.
28The air inlet temperature sensor (NTC), is
fitted in the air inlet duct between the air
cleaner and the hot mass air flow meter.
29A controlled canister purge valve is
actuated by the system. The tank ventilation is
monitored closely with the Lambda control (or
oxygen sensor) and adaptation by the
computer within the control unit.
30A knock control system is also fitted. This
eliminates the need for octane number
adjustment, as it is performed automatically
through the control unit.
Fuel and exhaust systems - fuel injection models 4B•3

1
Chapter 1
Routine maintenance and servicing
Air cleaner element - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Air inlet temperature control check . . . . . . . . . . . . . . . . . . . . . . . . . .28
Alternator V-belt check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Automatic transmission check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .34
Automatic transmission fluid level check . . . . . . . . . . . . . . . . . . . . . . .7
Automatic transmission fluid renewal . . . . . . . . . . . . . . . . . . . . . . . . .38
Bodywork check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
Brake fluid renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Brake pad check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
Brake shoe check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
Clutch cable check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
Coolant renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26
Distributor and HT lead check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
Door lock key battery - replacement . . . . . . . . . . . . . . . . . . . . . . . . .24
Driveshaft gaiter check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Exhaust system check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Fuel filter renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Handbrake linkage check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16Headlamp alignment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
Hose and fluid leak check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Idle speed and mixture - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . .9
Ignition timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
Intensive maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Lock and hinge check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
Manual transmission fluid check . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
Power steering fluid check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
Power steering pump drivebelt check . . . . . . . . . . . . . . . . . . . . . . . .18
Radiator inspection and cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Rear suspension level control system check . . . . . . . . . . . . . . . . . . .19
Road test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
Spark plug renewal (SOHC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Spark plug renewal (DOHC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Steering and suspension check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Throttle linkage maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Timing belt renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
Wiring check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
1•1
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

1•4Maintenance schedule
Every 250 miles (400 km) or weekly
MRefer to “Weekly checks”
Basic service, every 9000 miles
(15 000 km) or 12 months -
whichever comes sooner
Along with the items in “Weekly checks”, carry out the
following:
MRenew the engine oil and oil filter (Section 3).
MCheck all hoses and other components for fluid
leaks (Section 4).
MCheck the steering and suspension components
(Section 5).
MCheck the condition of the driveshaft rubber
gaiters (Section 6).
MCheck the automatic transmission fluid level (if
applicable), (Section 7).
MCheck the radiator for blockage (e.g. dead insects)
and clean as necessary (Section 8).
MCheck and adjust the idle speed and mixture (if
applicable), (Section 9).
MCheck the throttle linkage and lubricate if
necessary (Section 10).
MCheck the exhaust system for corrosion, leaks and
security (Section 11).
MCheck all wiring for condition and security
(Section 12).
MCheck and adjust the ignition timing (if applicable),
(Section 13).
MRenew the brake fluid (Section 14).
MCheck the brake pad friction material for wear
(Section 15).
MCheck the handbrake linkage (Section 16).
MCheck the power steering fluid level (if applicable),
(Section 17).
MCheck the power steering pump drivebelt (if
applicable), (Section 18).
MCheck the rear suspension level control system
height, if fitted (Section 19).
MCheck the bodywork (Section 20).
MLubricate all locks and hinges (Section 21).
MCheck the alternator V-belt (Section 22).
MCheck the headlamp alignment (Section 23).
MReplace battery in the door-lock key (if applicable),
(Section 24).
MCarry out a road test (Section 25).
Note: Vauxhall specify that an Exhaust Emissions Test should be
carried out at least annually. However, this requires special
equipment, and is performed as part of the MOT test (refer to the
end of the manual).
Full service, every 18 000 miles
(30 000 km) or 24 months -
whichever comes sooner
Along with the ‘basic service’, carry out the following:
MRenew the coolant (Section 26).
MRenew the air cleaner element (Section 27).
MCheck the operation of the air cleaner air inlet
temperature control (carburettor models only),
(Section 28).
MRenew the fuel filter (Section 29).
MRenew the spark plugs (SOHC only), (Section 30) *.
MInspect and clean the distributor cap and HT leads
(Section 31).
MCheck the clutch cable adjustment (Section 32).
MCheck the manual transmission oil level (Section 33).
MCheck the automatic transmission (Section 34).
MCheck the brake drum shoe for wear (Section 35).
Major service, every 36 000 miles
(60 000 km) or 48 months -
whichever comes sooner
Along with the ‘full service’, carry out the following:
MRenew timing belt (Section 36).
MRenew the spark plugs (DOHC models only),
(Section 37).
MRenew automatic transmission fluid (Section 38) *.
* Note: If a vehicle is used for heavy-duty work (e.g. taxi work,
caravan/trailer towing, mostly short-distance, stop-start city driving)
the fluid must be changed every 36 months or 27 000 miles (45 000
km), whichever occurs first.

28Air inlet temperature control
check (carburettor models
only)
2
Refer to Chapter 4A for details.
29Fuel filter renewal
3
Fuel filters are fitted in various locations
throughout the range. Some may be ‘in-line’ in
the fuel tank itself, or fitted into the
carburettor.
Refer to Chapters 4A or 4B, as appropriate.
30Spark plug renewal (SOHC)
2
1The correct functioning of the spark plugs is
vital for the correct running and efficiency of
the engine. It is essential that the plugs fitted
are appropriate for the engine. Refer to the
specifications in Chapter 5. If this type is used
and the engine is in good condition, the spark
plugs should not need attention between
scheduled service replacement intervals.
Spark plug cleaning is rarely necessary and
should not be attempted unless specialised
equipment is available, as damage can easily
be caused to the firing ends.
2Identify each HT lead for position so that the
leads can be refitted to their correct cylinders.
Then disconnect the leads from the plugs by
pulling on the connectors, not the leads.
3Clean the area around each spark plug
using a small paintbrush, then using a plugspanner (preferably with a rubber insert),
unscrew and remove the plugs (see
illustration). Cover the spark plug holes with
a clean rag to prevent the ingress of any
foreign matter.
4The condition of the spark plugs will tell
much about the overall condition of the
engine.
5If the insulator nose of the spark plug is
clean and white, with no deposits, this is a
sign of a weak mixture, or too hot a plug (a hot
plug transfers heat away from the electrode
slowly -a cold plug transfers heat away
quickly).
6If the tip and insulator nose is covered with
hard black-looking deposits, then this is
indicative that the mixture is too rich. Should
the plug be black and oily, then it is likely that
the engine is fairly worn, as well as the mixture
being too rich.
7If the insulator nose is covered with light tan
to greyish brown deposits, then the mixture is
correct, and it is likely that the engine is in
good condition.
8The spark plug gap is of considerable
importance, because if it is either too large or
too small, the size of the spark and its
efficiency will be seriously impaired. The spark
plug gap should be set to the figure given in
the Specifications, in Chapter 5.
9To set it, measure the gap with a feeler
blade and then bend open, or close, the outer
plug electrode until the correct gap is
achieved. The centre electrode should never
be bent, as this may crack the insulation and
cause plug failure, if nothing worse (see
illustrations).10Before fitting new spark plugs check that
their threaded connector sleeves are tight.
11Screw in the plugs by hand, then tighten
them to the specified torque. Do not exceed
the torque figure.
12Push the HT leads firmly onto the spark
plugs, ensuring that they are connected to
their correct cylinders.
31Distributor cap and HT lead
check
3
1Remove the distributor cap and HT leads,
and wipe them clean.
2Also wipe clean the coil connections.
Remove the rotor arm, then visually check the
distributor cap, rotor arm and HT leads for
hairline cracks, and signs of arcing.
1•14Every 18 000 miles or 24 months
30.9A Tools required for spark plug
removal, gap adjustment and refitting30.9C Measuring the spark plug gap with
feeler blade30.9B Measuring the spark plug gap with
wire gauge
30.3 Removing a spark plugWarning: Before carrying out
the following operation, refer to
the precautions given in “Safety
first!” at the beginning of this
manual, and follow them implicitly. Petrol
is a highly dangerous and volatile liquid,
and the precautions necessary when
handling it cannot be overstressed.
It is very often difficult to insert spark
plugs into their holes without cross-
threading them. To avoid this, fit a
short length of 8 mm (internal
diameter), rubber hose over the end of
the spark plug. The flexible hose acts
as a universal joint to help align the
plug correctly. Should the plug begin to
cross-thread, the hose will slip on the
spark plug, preventing damage to the
thread in the cylinder head.
Number the HT leads before
removal to ensure correct
refitting.

Torque wrench settings (continued)Nmlbf ft
Starter to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4533
Starter support to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Temperature regulator plug (M20) * . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Timing belt cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Timing belt drive gear to crankshaft: *
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250184
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by between 40°and 50°
Timing belt guide roller bracket to block . . . . . . . . . . . . . . . . . . . . . . . .2518
Timing belt guide roller to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Timing belt guide roller to cylinder block:
Engines up to 1993
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by 45°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by 15°
1993-on engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Transfer box bracket to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . .6044
Transmission to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6044
1General
This part of Chapter 2 describes
procedures that are specific to the DOHC
engine. It should be read in conjunction with
Part A.
The lower engine is basically the same as
the 2.0 litre SOHC. However the pistons are
attached to the connecting rods by gudgeon
pins, which are fully floating, and are secured
by circlips.
Both camshafts on these engines are driven
from the crankshaft by one toothed
composite rubber belt. Each cylinder has four
valves (two inlet and two exhaust), operated
directly from the camshafts by hydraulic
self-adjusting valve lifters. One camshaft
operates the inlet valves, and the other
operates the exhaust valves.
DOHC models are fitted with a remotely
mounted oil cooler.
The distributor is driven directly from the
exhaust camshaft.
2Engine - removal and refitting
4
Removal
1Carry out procedure in Chapter 2A, noting
the following differences.
2With the car safely raised, remove the
engine undershield.
3The fuel hoses need to be disconnected
from the fuel rail.
4Disconnect coolant hoses from the cylinder
block and cylinder head. Also disconnect the
oil cooler pipe unions from the oil pump.
5Unbolt the right-hand driveshaft centre
bearing support bracket from the rear of the
cylinder block.
Refitting
6Refitting the engine is similar to theprocedure in Chapter 2A. The exceptions
being, replacement of the right-hand
driveshaft centre bearing support bracket at
the rear of the cylinder block and retightening
the securing bolts.
7Replace the undershield.
3Engine/transmission
mountings- renewal
3
The procedure for replacing the engine/
transmission is similar to SOHC models, see
Chapter 2A. However this engine is fitted with
an undershield that needs to be removed
before replacing the mounts. Do not forget to
replace the undershield before lowering the
car.
4Timing belt, sprockets and belt
tensioner and idler pulleys-
removal, refitting and adjustment
3
Note: The timing belt should be renewed on
refitting. A two-legged puller may be required
to remove the crankshaft sprocket
Removal
1Disconnect the battery negative lead.2Disconnect the air cleaner trunking from the
airflow meter, then remove the cover and the
air cleaner element from the air cleaner. If
desired, for improved access, the complete
air cleaner assembly can be removed, as
described in Chapter 4B.
3Remove the power steering pump drivebelt,
as described in Chapter 10.
4Remove the alternator drivebelt, as
described in Chapter 5.
5Remove the three securing screws, and
withdraw the outer timing belt cover. Recover
the rubber grommets from the screw holes in
the cover if they are loose.
6Turn the crankshaft using a Torx socket on
the crankshaft sprocket bolt, until the timing
marks on the camshaft sprockets are aligned
with the notches in the camshaft cover. The
notch in the crankshaft pulley should also be
aligned with the pointer on the rear timing belt
cover (see illustrations).
7Extract the six securing bolts using a
splined bit, and withdraw the crankshaft
pulley (see illustration). If necessary,
counterhold the crankshaft using a socket on
the crankshaft sprocket bolt. If the engine is in
the vehicle, the crankshaft can be prevented
from turning by having an assistant engage
first gear and depress the brake pedal.
Alternatively, the flywheel ring gear teeth can
be jammed using a large screwdriver or
similar tool. Before removing the pulley, check
that the timing marks are still aligned.
DOHC engine procedures 2B•3
4.6B . . .and notch in crankshaft pulley
aligned with pointer on rear timing belt
cover (circled)4.6A Camshaft sprocket TDC mark
aligned with notch in camshaft cover
2B

pitting. If evident, the cylinder head and all
bearing caps must be renewed as a matched
set, as there is no provision for refacing if the
bearing caps cannot be renewed individually.
8The camshaft(s) should show no marks or
scoring on the journal or cam lobe surfaces. if
evident, renew the camshaft(s).
9It is advisable to renew the camshaft front
oil seal(s) as a matter of course. Prise the old
seal(s) from the front of the camshaft(s) and
discard them.
Refitting
10Begin refitting by liberally coating the
contact faces of the hydraulic valve lifters and
the camshaft(s) with molybdenum disulphide
paste.
11Coat the mating faces of the front and
rear bearing caps with sealing compound and
refit the bearing caps in their original positions
as noted during removal.
12Tighten the camshaft bearing cap nuts to
the specified torque in half-turn stages, as
when loosening the nuts. Note that when
refitting the exhaust camshaft, the two smaller
rear bearing cap securing nuts should be
tightened after all the main camshaft bearing
cap nuts have been tightened. Note also that
the two smaller nuts should be tightened to a
lower torque wrench setting than the main
nuts.
13Turn the camshaft until the locating peg
for the camshaft sprocket is uppermost, then
lubricate the lips of a rear camshaft front oil
seal with a little grease, and fit the oil seal,
using a tube or socket of similar diameter with
a washer and the camshaft sprocket bolt.
Screw the camshaft sprocket bolt into the end
of the camshaft to draw the oil seal into
position on its shoulder.
14Repeat the procedure for the remaining
camshaft.
15Refit the distributor with reference to
Chapter 5. Fit a new timing belt and the
camshaft sprockets, then adjust the timing
belt as described in Section 4 or 5, as
applicable.
8Cylinder head -removal and
refitting (engine in vehicle)
4
Note: The engine must be cold when the
cylinder head is removed. Do not remove the
cylinder head from a hot engine. New cylinder
head bolts, a new cylinder head gasket and a
new timing belt must be used on refitting.
The torque settings (as shown in Chapter 2A)
are only applicable to latest specification head
bolts, available from Vauxhall. Earlier type or
alternative make, head bolts may require
different torques. Consult your supplier
Removal
1Disconnect the battery negative lead.
2Drain the cooling system, as described in
Chapter 3.3Remove the front section of the exhaust
system, as described in Chapter 4C.
4The cylinder head can be removed
complete with the inlet manifold, or the inlet
manifold can be detached from the cylinder
head before removal, with reference to
Chapter 4B. If no work is to be carried out on
the inlet manifold, it can be unbolted from the
cylinder head and supported to one side out
of the way, thus avoiding the need to
disconnect the relevant hoses, pipes and
wiring.
5If the cylinder head is to be removed
complete with the inlet manifold, disconnect
all relevant hoses, pipes and wiring from the
inlet manifold and associated components,
referring to Chapter 4B, and unbolt the
manifold support bracket from the manifold.
Loosen the alternator mountings with
reference to Chapter 5, then unbolt the upper
alternator mounting from the inlet manifold.
6If the inlet manifold is to be left in the engine
compartment, continue as follows, otherwise
go on to paragraph 17.
7Disconnect the wiring plug from the airflow
meter, and the breather hose from the air box
on the throttle body. Disconnect the air
cleaner trunking and remove the airflow
meter/air box assembly from the throttle
body. Refer to Chapter 4B if necessary.
8Disconnect the end of the throttle cable
from the throttle valve lever, then unbolt the
throttle cable support bracket and remove it
from the inlet manifold.
9Unscrew the two earth lead securing nuts
from the fuel rail (one at each end of the rail)
and disconnect the three earth leads.
10Disconnect the wiring plug from the
throttle position switch.
11Pull up on the wiring harness housing, and
disconnect the wiring plugs from the fuel
injectors by compressing the retaining clips.
Move the wiring harness housing to one side.
12Disconnect the two breather hoses from
the rear of the camshaft cover.
13Loosen the alternator mountings, with
reference to Chapter 5, then unbolt the upper
alternator mounting from the inlet manifold.
14Unbolt the manifold support bracket from
the manifold.15Make a final check to ensure that all
necessary hoses, pipes and wires have been
disconnected, then unscrew the securing nuts
and lift the inlet manifold from the cylinder
head. Ensure that the manifold is properly
supported, taking care not to strain any of the
hoses, pipes and wires, etc., which are still
connected.
16Recover the manifold gasket from the
cylinder head.
17Remove the timing belt, camshaft
sprockets, and timing belt tensioner and idler
pulleys, as described in Section 4.
18Unscrew the upper and middle studs for
the timing belt outer cover screws. Note that
the upper stud simply unscrews from the
cylinder head, but the middle stud is secured
by a bolt.
19Unscrew the two upper rear timing belt
cover securing bolts from the cylinder head.
20Remove the distributor cap and HT leads
with reference to Chapter 5.
21Disconnect the distributor wiring plug.
22Disconnect the coolant hose from the
left-hand end of the cylinder head.
23Unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
24Disconnect the radiator top hose from the
thermostat housing, and disconnect the
wiring plugs from the temperature gauge
sender and the coolant temperature sensor
(both situated in the thermostat housing).
25Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
26On X20 XEV models, remove the
camshaft, as described in Section 7.
27Using a Torx socket, and working in the
order shown (see illustrations), loosen all the
cylinder head bolts by a quarter of a turn, then
loosen all the bolts by half a turn, and finally
loosen and remove the bolts. Recover the
washers. Note that the loosening sequence
on X20 XEV differs to other DOHC engines.
28Lift the cylinder head from the cylinder
block. If necessary, tap the cylinder head
gently with a soft-faced mallet to free it from
the block, but do not lever at the mating
faces. Note that the cylinder head is located
on dowels.
DOHC engine procedures 2B•7
8.27B Cylinder head bolt loosening
sequence - (X 20 XEV engines)8.27A Cylinder head bolt loosening
sequence - (20 XEJ and C 20 XE engines)
2B

29Recover the cylinder head gasket and
discard it.
30Clean the cylinder head and block mating
faces by careful scraping. Take care not to
damage the cylinder head, which is made of
light alloy and is easily scored. Cover the
coolant passages and other openings with
masking tape or rag, to prevent dirt and
carbon falling in. Mop out all the oil from the
bolt holes; if oil is left in the holes, hydraulic
pressure could crack the block when the bolts
are refitted.
31If desired, the cylinder head can be
dismantled and inspected as described in
Section 10.
Refitting
32Begin refitting by locating a new gasket
on the block so that the word “OBEN” or
“TOP” is uppermost at the timing belt end of
the engine.
33With the mating faces scrupulously clean,
locate the cylinder head on the block so that
the positioning dowels engage in their holes.
34Temporarily refit the crankshaft pulley and
the camshaft sprockets, and ensure that the
timing marks are still positioned as they were
before the timing belt was removed (see
Section 4).35Fit the new cylinder head bolts, ensuring
that the washers are in place under their
heads, and screw the bolts in by hand as far
as possible.
36Tighten the bolts in the order shown (see
illustrations). Note that the tightening
sequence on X20 XEV differs to other DOHC
engines. Tighten the bolts in the four stages
given in the Specification (see Chapter 2A, as
2.0 litre) - i.e. tighten all bolts to the Stage 1
torque, then tighten all bolts to Stage 2 and so
on (see illustrations).
37Further refitting is a reversal of the
removal procedure, remembering the
following points.
38Refit the timing belt tensioner and idler
pulleys, camshaft sprockets and a new timing
belt as described in Section 4, and tension the
timing belt as described in Sections 4 and 5.
39Where applicable, refit the inlet manifold
to the cylinder head with reference to Chapter
4B, using a new gasket.
40Refit the front section of the exhaust
system as described in Chapter 4C, using a
new gasket.
41Refit the upper alternator mounting to the
inlet manifold (where applicable), then adjust
the alternator drivebelt tension, as described
in Chapter 5.
42Refill the cooling system, (Chapter 3).43On completion, check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
44When the engine is started, check for
signs of leaks.
45Once the engine has reached normal
operating temperature, check and if
necessary adjust the mixture (where
applicable) with reference to Chapter 4B.
9Cylinder head -removal and
refitting (engine removed)
4
Note: New cylinder head bolts, a new cylinder
head gasket, and a new timing belt must be
used on refitting.
The torque settings (as shown in Chapter 2A)
are only applicable to latest specification head
bolts, available from Vauxhall. Earlier type or
alternative make, head bolts may require
different torques. Consult your supplier.
Removal
1The cylinder head can be removed
complete with the inlet manifold, or the inlet
manifold can be detached from the cylinder
head before removal, with reference to
Chapter 4B.
2Proceed as described in Section 8,
paragraphs 17 to 19 inclusive.
3If not already done, remove the distributor
cap and HT leads, referring to Chapter 5.
2B•8DOHC engine procedures
8.36A Cylinder head bolt tightening sequence -
20 XEJ and C 20 XE engines
8.36C Tighten the cylinder head bolts to
the specified torque . . .8.36D . . .and then through the specified
angle
8.36B Cylinder head bolt tightening sequence -
X 20 XEV engines
Warning: The exhaust valves
fitted to 20 XEJ and C 20 XE
models are fitted with sodium to
improve their heat transfer.
Sodium is a highly reactive metal, which
will ignite or explode spontaneously on
contact with water (including water vapour
in the air). These must NOT be disposed of
with ordinary scrap. Seek advice from a
Vauxhall dealer or your Local Authority, if
the valves are to be disposed.