1988 OPEL CALIBRA warning

Refitting
5Refitting is a reversal of the removal
procedure, ensuring that the wiring plugs are
correctly reconnected and that the unit is
located securely.
36Knock sensor and module
(X16 SZ models) - removal
and refitting
3
Removal
1The knock sensor fitted to the X16 SZ
engine is located on the cylinder block below
the inlet manifold, between cylinders 2 and 3.
2Disconnect the battery negative lead.
3Remove the wiring and unscrew the unit
from the block.
4The module and control unit are located on
the left-hand side of the engine compartment
behind the battery. To remove, disconnect the
wiring multiplug and remove the retaining
bolts (see illustration).
5There is no provision for testing the knock
sensor or module without dedicated Vauxhall
test equipment. Check for external damage
and replace if necessary.
Refitting
6Refitting is a reversal of the removal
procedure, ensuring that the wiring plugs are
correctly reconnected and that the units are
located securely.
37Knock sensor (Simtec
system) - removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Disconnect wiring harness plug, from inlet
air temperature sensor and wiring harness
plug, from hot mass air flow meter.
3Remove crankcase ventilation hoses.
4Remove coolant hoses from air inlet hoses,
hot film mass air flow meter complete with air
inlet hoses, from upper part of air cleaner and
throttle body.5Press retaining clip for 1st and 4th cylinder
injectors in plug strip (with screwdriver)
towards fuel distributor pipe - lifting plug strip
at the same time. On the underside of the plug
strip there are a total of 6 plug connections, 4
of which are for the injectors.
6Disconnect wiring harness plug for knock
sensor from the plug strip.
7Connect a 1 metre length of separate cable
to knock sensor wiring harness plug (note
routing).
8Remove knock sensor from cylinder block
(see illustration).
9Disconnect knock sensor cable from
separately attached cable, separate cable
remains in engine compartment.
Refitting
10Refitting is a reversal of removal, but note
the following.
11Before refitting ensure that the sensor is
spotlessly clean. Clean the entire contact
surface of the sensor must lie directly on the
cylinder block. Do not use any form of
washers.
12Carefully refit sensor into the block.
Tighten to the correct torque.
13Guide knock sensor cable between ridges
on inlet manifold using separate cable -
ensure correct routing.
14Remove the cable.
15Insert the wiring harness plug for the
knock sensor, into the plug strip.
16Correctly align the spring clips for theinjectors as they may prevent engagement of
the plug strip. Correct contact between the
plug strip and the injector is essential.
17When connecting plug strip, an audible
‘click’ should be heard.
18Ensure that hoses are in good condition
and installed securely with the two clamps.
38Inlet manifold (SOHC without
Multec) - removal and refitting
3
Note:Refer to warning in Section 2, before
proceeding. Use a new gaskets when refitting.
Removal
1Disconnect the battery negative lead.
2Remove the idle speed adjuster and its
hoses, referring to Section 22, if necessary.
3Release the securing clip, then disconnect
the throttle cable and balljoint from the throttle
valve lever. Slide the throttle cable grommet
from the bracket on the inlet manifold, and
move the throttle cable to one side out of the
way.
4Loosen the clamp screw and disconnect
the air trunking from the throttle body.
5Unscrew the union nut and disconnect the
brake servo vacuum hose from the inlet
manifold(see illustration).
6Disconnect the camshaft cover breather
hose from the throttle body.
7Disconnect the coolant hoses from the
throttle body. Be prepared for coolant
spillage, and clamp or plug the open ends of
the hoses, to prevent further coolant loss.
8Disconnect the wiring plug from the throttle
position sensor.
9Disconnect the vacuum pipe from the top
of the fuel pressure regulator.
10Disconnect the wiring harness housing
from the fuel injectors and move it to one side,
taking care not to strain the wiring. Pull up on
the wiring harness housing, and compress the
wiring plug retaining clips to release the
harness housing from the injectors.
11Disconnect the fuel hoses from the fuel
rail. Be prepared for fuel spillage, and take
adequate fire precautions. Clamp or plug the
open ends of the hoses, to prevent dirt
ingress and further fuel leakage.
Fuel and exhaust systems - fuel injection models 4B•17
38.5 Disconnecting the brake servo
vacuum hose -
SOHC models37.8 Knock sensor and wiring
(Simtec system)
1 Sensor2 Securing bolt
36.4 Knock sensor and module (X16 SZ models)
1 Sensor2 Module3 Sensor securing bolt
4B

test (refer to Chapter 2A) will provide valuable
information regarding the overall performance
of the main internal components. Such a test
can be used as a basis to decide on the
extent of the work to be carried out. If, for
example, a compression test indicates serious
internal engine wear, conventional
maintenance as described in this Chapter will
not greatly improve the performance of the
engine. It may also prove a waste of time and
money, unless extensive overhaul work is
carried out first.
The following series of operations are those
most often required to improve the
performance of a generally poor-running
engine:Primary operations
a)Clean, inspect and test the battery (See
“Weekly Checks”)
b)Check all the engine related fluids (See
“Weekly Checks”)
c)Check the condition and tension of the
auxiliary drivebelt (Sections 18 and 22, as
appropriate).
d)Renew the spark plugs (Sections 30 and
37, as appropriate).
e)Inspect the distributor cap, rotor arm and
HT leads, as applicable (Section 31).
f)Check the condition of the air filter, and
renew if necessary (Section 27).
g)Check the fuel filter (Section 29).
h)Check the condition of all hoses, and
check for fluid leaks (Section 4).i)Check the idle speed and mixture
settings, as applicable (Section 9).
5If the above operations do not prove fully
effective, carry out the following secondary
operations:
Secondary operations
All items listed under “Primary operations”,
plus the following:
a)Check the charging system (Chapter 5).
b)Check the ignition system (Chapter 5).
c)Check the fuel system (Chapters 4A and
4B).
d)Renew the distributor cap and rotor arm
(Section 31).
e)Renew the ignition HT leads (Section 31).
3Engine oil and filter - renewal
2
1Ideally, the oil should be drained with the
engine hot, just after the vehicle has been
driven.
2On DOHC models, remove the engine
undershield to expose the sump drain plug
and the oil filter.
3Place a container beneath the oil drain plug
at the rear of the sump.
4Remove the oil filler cap from the camshaft
cover, then using a socket or spanner,
unscrew the oil drain plug, and allow the oil to
drain (see illustration). Take care to avoid
scalding if the oil is hot.
5Allow ten to fifteen minutes for the oil to
drain completely, then move the container
and position it under the oil filter.6On 1.8 and 2.0 litre models, improved
access to the oil filter can be gained by
jacking up the front of the vehicle and
removing the right-hand roadwheel (see
illustration). Ensure that the handbrake is
applied, and that the vehicle is securely
supported on axle stands (see “Jacking and
Vehicle Support”). Note that further oil may
drain from the sump as the vehicle is raised.
7Using a strap wrench or a filter removal tool
if necessary, slacken the filter and unscrew it
from the mounting. Alternatively, if the filter is
very tight, a screwdriver can be driven
through the filter casing and used as a lever.
Discard the filter.
8Wipe the mating face on the filter mounting
with a lint-free rag, then smear the sealing ring
of the new filter with clean engine oil of the
specified grade.
9Screw the new filter into position and
tighten it by hand only, do not use any tools.
10Where applicable, refit the roadwheel and
lower the vehicle to the ground. Fully tighten
the roadwheel bolts with the vehicle resting on
its wheels.
11Examine the condition of the oil drain plug
sealing ring and renew if necessary, then refit
the drain plug and tighten it to the specified
torque. 12Refill the engine through the filler on the
camshaft cover, using the specified grade and
quantity of oil. Fill until the level reaches the
“MAX” mark on the dipstick, allowing time for
the oil to drain through the engine to the
sump.
13Refit the oil filler cap, then start the engine
and check for leaks. Note that the oil pressure
warning lamp may stay illuminated for a few
seconds when the engine is started as the oil
filter fills with oil.
14Stop the engine and recheck the oil level,
topping-up if necessary.
15On DOHC models, refit the engine
undershield.
16Dispose of the old engine oil safely; do not
pour it down a drain.
4Hose and fluid leak check
1
1Visually inspect the engine joint faces,
gaskets and seals for any signs of water or oil
leaks. Pay particular attention to the areas
around the camshaft cover, cylinder head, oil
filter and sump joint faces. Remember that,
over a period of time, some very slight
seepage from these areas is to be expected -
what you are really looking for is any
indication of a serious leak. Should a leak be
found, renew the offending gasket or oil seal
by referring to the appropriate Chapters in this
manual.
Every 9000 miles or 12 months 1•9
3.6 Oil filter viewed through right-hand
wheel arch - SOHC model3.4 Sump drain plug location -
2.0 litre DOHC model
(engine undershield removed)
1
Basic service, every 9000 miles (15 000 km) or 12 months
As the drain plug releases
from the threads, move it
away quickly so the stream
of oil, running out of the
sump, goes into the container not up
your sleeve (see illustration).
Note: It is
antisocial and
illegal to dump oil
down the drain.
To find the
location of your
local oil recycling
bank, call this
number free.

At the same time, check the general
condition of the CV joints themselves by first
holding the driveshaft and attempting to
rotate the wheel. Repeat this check by holding
the inner joint and attempting to rotate the
driveshaft. Any appreciable movement
indicates wear in the joints, wear in the
driveshaft splines, or a loose driveshaft
retaining nut.
7Automatic transmission fluid
level check
2
Note: The transmission fluid level can be
checked either when it is cold (only below
35ºC (100ºF) outside temperature) or when it is
fully warmed up to normal operating
temperature (after driving for a distance of
approximately 12 miles/20 km). Since the fluid
level must be checked with the engine
running, ensure that the vehicle is parked on
level ground with the handbrake firmly applied
before leaving the driver’s seat. Be careful to
keep loose clothing, long hair, etc., well clear
of hot or moving components when working
under the bonnet
Transmission cold
1Park the vehicle on level ground and apply
the handbrake firmly. With the engine running
at no more than idle speed and your foot
firmly on the brake pedal, move the selector
lever through all positions, ending in position
“P”. Allow the engine to idle for one minute,
then check the level within two minutes.
2With the engine still idling and position “P”
still selected, open the bonnet and withdraw
the transmission dipstick from the filler tube
located in the front of the transmission casing,
at the left-hand end of the engine.
3Note the fluid’s condition (see below), then
wipe clean the dipstick using a clean,
non-fluffy rag, insert it fully back into the tube
and withdraw it again.
4The level should be up to the “MAX” mark
on the “+20°C” side of the dipstick (see
illustration).
5If topping-up is required, switch off the
ignition and add only good quality fluid of the
specified type through the filler tube. Ifsignificant amounts of fluid are being lost
(carefully note the amounts being added, and
how often), check the transmission for leaks
and either repair the fault or take the vehicle to
a Vauxhall dealer for attention.
6When the level is correct, ensure that the
dipstick is pressed firmly into the filler tube.
Transmission fully warmed up
7Work exactly as described above, but take
the level reading from the “+ 80°C” side of the
dipstick. In this case, the level must be
between the dipstick “MAX” and “MIN”
marks.
Checking the fluid’s condition
8Whenever the fluid level is checked,
examine the condition of the fluid and
compare its colour, smell and texture with that
of new fluid.
9If the fluid is dark, almost black, and smells
burnt, it is possible that the transmission
friction material is worn or disintegrating. The
vehicle should be taken to a Vauxhall dealer
or automatic transmission specialist for
immediate attention.
10If the fluid is milky, this is due to the
presence of emulsified droplets of water. This
may be caused either by condensation after a
prolonged period of short journeys or by the
entry of water through the dipstick/filler tube
or breather. If the fluid does not revert to its
normal appearance after a long journey it
must be renewed or advice should be sought
from a Vauxhall dealer or automatic
transmission specialist.
11If the fluid is varnish-like (i.e. light to dark
brown and tacky) it has oxidised due to
overheating or to over or under filling. If
renewal of the fluid does not cure the
problem, the vehicle should be taken to a
Vauxhall dealer or automatic transmission
specialist for immediate attention.
12If at any time on checking the fluid level or
on draining the fluid, particles of dirt, metal
chips or other foreign matter are found in the
fluid, the vehicle must be taken to a Vauxhall
dealer or automatic transmission specialist for
immediate attention. It may be necessary to
strip, clean and reassemble at least the valve
body, if not the complete transmission, to
rectify any fault.
8Radiator inspection and
cleaning
1
1Inspect radiator for leaks or corrosion,
especially around the outlet or inlet
connectors.
2Clean the radiator with a soft brush or
compressed air. Remove any debris, like dead
insects or leaves.
3If leaks are visible, replace radiator. Refer to
Chapter 3, if necessary.
9Idle speed and mixture -
adjustment
2
Note: On certain models, the idle and mixture
are automatically adjusted by a control unit,
therefore cannot be altered.
Refer to Chapters 4A or 4B as applicable.
10Throttle linkage
maintenance
2
On models built before 1992, lubricate the
throttle linkage, as described in Chapters 4A
or 4B, as applicable.
11Exhaust system check
2
1With the engine off, check the security of
the exhaust system. Pay particular attention
to the rubber mountings that suspend the
exhaust.
2Start the engine and check underneath for
leaks, which can be heard. This job is made
easier if you have access to a ramp.
3Listen for exhaust leaks from around the
front pipe to exhaust manifold joint.
4For further information, refer to Chapter 4C
12Wiring check
1
1Check all wiring in both the engine
compartment and under the car.
2Ensure that all wiring clips/clamps are secure.
3Pay particular attention to wiring near
components that get hot, i.e. exhaust
systems.
4Make sure that electrical connections are
secure and undamaged.
13Ignition timing
3
Refer to Chapter 5 for details.
Every 9000 miles or 12 months 1•11
7.4 When checking the fluid level, ensure
side of dipstick used corresponds with
fluid temperature
1
Warning: Voltages produced by
an electronic ignition system
are considerably higher than
those produced by conventional
ignition systems. Extreme care must be
taken when working on the system with
the ignition switched on. Persons with
surgically implanted cardiac pacemaker
devices should keep away from the
ignition circuits, components and test
equipment.

14Brake fluid renewal
3
Renew the brake and bleed the system.
Refer to Chapter 9 for full details.
15Brake pad check
2
With the front or rear (as applicable) of the
vehicle raised, remove the wheels and check
brake pads for wear. Renew the pads if the
lining is below that specified. See Chapter 9,
for specifications and full details.
16Handbrake linkage check
2
With the vehicle raised, check the operation
of the handbrake and lubricate the linkages.
Refer to Chapter 9, for further details.
17Power steering fluid check
2
1With the engine off, remove the cap from
the power steering reservoir. It is fitted with a
dipstick.
2The fluid should be visible up to the ‘MAX’
mark (1), (see illustration). If not, top it up
using specified fluid.
3Start the engine and immediately top-up
the fluid to the ‘MIN’ mark (2).
4Do not allow the reservoir to run dry.
5For details on how to bleed the system,
refer to Chapter 10.
18Power steering pump
drivebelt check
2
Note:Vauxhall specify the use of a special
gauge. Checking values for use with this
gauge are given in the Specifications in
Chapter 10, for reference.
Checking
1The correct belt tension can be
approximated by adjusting the length of the
threaded rod. This should give a belt
deflection of approximately 10.0 mm (0.4 in)
under moderate thumb pressure at the
midpoint of the belt run between the pulleys. If
in doubt, err on the slack side, as an
excessively tight belt may cause pump
damage.
2Check the condition of the belt and renew it
if there are any signs of damage or excessive
wear
Adjustment
3Slacken the adjuster and mounting bolts.
4Slacken the adjuster nuts, and adjust the
length of the threaded rod to remove or
tension the belt as desired (see illustration).
5Tighten the adjuster nuts, and tighten the
adjuster and mounting bolts to the specified
torque (see Chapter 10), on completion.
6If a new drivebelt has been fitted, recheck
the tension after a few hundred miles.
19Rear suspension level
control system check
2
Refer to Chapter 10, for details.
20Bodywork check
1
1Clean the outside of the vehicle. If possible,
clean underneath as well. If using a pressure
cleaner take care not to damage any electrical
components, especially in the engine
compartment.
2Check all around for signs of damage or
corrosion and treat accordingly. Repair stone
chips when you can to prevent rusting.
3Read Chapter 11, for more details.
21Lock and hinge check
2
1Lubricate locks and hinges on all doors,
tailgates (or boot lid) and bonnet.
2Check for wear or damage and ensure
correct operation of safety catches.
3Check security of the bonnet stay and it’s
securing clip.
4Read Chapter 11, for further details.
22Alternator V-belt check
2
Note:The new ribbed V-belt, fitted to later
models, can not be adjusted.
1Although special tools are available for
measuring the belt tension, a good
approximation can be achieved. Tension the
belt so that there is approximately 13.0 mm
(0.5 in) of free movement under firm thumb
pressure at the mid-point of the longest run
between pulleys.
2With the mounting bolts just holding the
unit, lever the alternator away from the engine
using a wooden lever at the mounting bracket
end until the correct tension is achieved. Then
1•12Every 9000 miles or 12 months
17.2 Topping-up the power steering fluid
level
18.4 Adjusting the length of the power
steering pump threaded rod
Warning: Brake hydraulic fluid
can harm your eyes and
damage painted surfaces, so
use extreme caution when
handling and pouring it. Do not use fluid
that has been standing open for some
time, as it absorbs moisture from the air.
Excess moisture can cause a dangerous
loss of braking effectiveness.
Old hydraulic fluid is usually
darker in colour than new
fluid.
For a quick check, the thickness of the
friction material on each brake pad can
be measured through the aperture in
the caliper body.

tighten the mounting nuts and bolts. On no
account lever at the free end of the alternator,
as serious internal damage could be caused.
3For details of replacement, see Chapter 5.
23Headlamp alignment
2
Refer to Chapter 12 for details.
24Door lock key battery -
replacement
1
1Carefully prise open the outer cover from
the key. Take care not to lose any of the
internal components, as they are loose.
2Remove the battery and discard it safely.
3Place the new battery, “+” side up (see
illustration). Check the operation of the key. If
the bulb does not light obtain a replacement.
4Replace the outer cover.
25Road test
1
Instruments and electrical
equipment
1Check the operation of all instruments and
electrical equipment.
2Make sure that all instruments read
correctly, and switch on all electrical
equipment in turn to check that it functions
properly.
Steering and suspension
3Check for any abnormalities in the steering,
suspension, handling or road “feel”.
4Drive the vehicle, and check that there are
no unusual vibrations or noises.5Check that the steering feels positive, with
no excessive “sloppiness”, or roughness, and
check for any suspension noises when
cornering, or when driving over bumps.
Drivetrain
6Check the performance of the engine,
clutch, transmission and driveshafts.
7Turn the radio/cassette off and listen for
any unusual noises from the engine, clutch
and transmission.
8Make sure that the engine runs smoothly
when idling, and that there is no hesitation
when accelerating.
9Check that the clutch action is smooth and
progressive, that the drive is taken up
smoothly, and that the pedal travel is not
excessive. Also listen for any noises when the
clutch pedal is depressed.
10Check that all gears can be engaged
smoothly, without noise, and that the gear
lever action is not abnormally vague or
“notchy”.
11Listen for a metallic clicking sound from
the front of the vehicle, as the vehicle is driven
slowly in a circle with the steering on full lock.
Carry out this check in both directions. If a
clicking noise is heard, this indicates wear in a
driveshaft joint, in which case, the complete
driveshaft must be renewed (see Chapter 8).
26Coolant renewal
2
Refer to Chapter 3 for details.
27Air cleaner element - renewal
2
Early round type
1Release the spring clips from the perimeter
of the air cleaner cover.
2Unscrew and remove the small cross-head
screw securing the cover extension to the
main body near the inlet duct.3Unscrew and remove the three central
cross-head cap nuts securing the air cleaner
to the carburettor, taking care not to drop the
washers and seals (see illustration).
4Separate the cover from the main body,
then lift out the element (see illustration).
5Wipe clean the inside surfaces of the cover
and main body.
6Locate the new element in the air cleaner
body, and refit the cover using a reversal of
the removal procedure.
Square type with air box
7If desired, to improve access, unclip the
coolant expansion tank hose from the air
cleaner cover.
8Release the two clips from the left-hand
side of the cover, and unscrew the two
screws from the right-hand side, then lift the
cover sufficiently to remove the element.
9Wipe clean the inside surfaces of the cover
and main body.
10Refitting is a reversal of removal, noting
that the element fits with the rubber locating
flange uppermost.
Every 18 000 miles or 24 months 1•13
24.3 Replacing the battery in the door lock
key
1 Battery (note, positive ‘+’ side up)
2 Bulb
27.4 Removing the air cleaner element -
note clip for crankcase ventilation hose
(arrowed)
27.3 Air cleaner-to-carburettor mounting
cap nuts
1
Full service, every 18 000 miles (30 000 km) or 24 months
Warning: Wait until the engine is
cold before starting the
procedure. Do not allow
antifreeze to come in contact
with your skin or with painted surfaces of
the vehicle. Rinse off spills with plenty of
water. Never leave antifreeze lying around
in an open container. Always clean spilt
fluids, as it can be harmful if swallowed.

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.

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.

the cylinder head above the camshaft(s)
through a hose. From here the gases are
drawn into the inlet manifold/throttle body (as
applicable) and/or the air box on the
carburettor (where applicable), where they are
re-burnt with fresh air/fuel mixture, hence
reducing harmful exhaust emissions.
Maintenance
3Certain models have a mesh filter inside the
camshaft cover, which should be cleaned in
paraffin if clogging is evident (see
illustration).
4On high mileage vehicles, particularly when
regularly used for short journeys, a jelly-like
deposit may be evident inside the crankcase
ventilation system hoses. If excessive
deposits are present, the relevant hose(s)
should be removed and cleaned.
5Periodically inspect the system hoses for
security and damage, and renew as
necessary. Note that damaged or loose hoses
can cause various engine running problems
that can be difficult to trace.
6The crankcase breather/dipstick tube can
be unbolted from the cylinder block after
disconnecting the hose. Use a new gasket
when refitting.
3Compression test -
description
3
Description
1If engine performance is poor, or if misfiring
occurs which cannot be attributed to the
ignition or fuel system, a compression test
can provide diagnostic clues. If the test is
performed regularly, it can give warning of
trouble on a high mileage engine before any
other symptoms become apparent.
2The engine must be at operating
temperature, the battery must be fully
charged, and the spark plugs must be
removed. The help of an assistant will also be
required.
3Disable the ignition system by
disconnecting the coil LT (“+15”) wire. Fit the
compression tester to No 1 cylinder spark
plug hole.4Have the assistant hold the throttle wide
open and crank the engine on the starter.
Record the highest reading obtained on the
compression tester.
5Repeat the test on the remaining cylinders,
recording the pressure developed in each.
6The difference in pressure between any two
cylinders should be no more than 1.0 bar
(14.5 lbf/in2). If the pressure in any cylinder is
low, pour a teaspoonful of clean engine oil
into the spark plug hole, and repeat the test.
7If the addition of oil temporarily improves
the compression pressure, this indicates that
cylinder bore or piston ring wear was
responsible for the pressure loss. No
improvement suggests that leaking or burnt
valves, or a blown head gasket may be to
blame.
8A low reading from two adjacent cylinders
is almost certainly due to the head gasket
leaking between them.
9On completion of the test, refit the spark
plugs and reconnect the coil LT wire.
4Major operations possible
with the engine in the vehicle
1The following operations may be carried out
without removing the engine from the vehicle:
a)Removal and refitting of oil pressure relief
valve (see Section 30)
b)Removal and refitting of timing belt and
sprockets
c)Removal and refitting of camshaft housing
(SOHC engines)
d)Removal and refitting of camshaft(s)
e)Removal and refitting of cylinder head
f)Removal and refitting of sump
g)Removal and refitting of oil pump
h)Removal and refitting of
piston/connecting rod assemblies
i)Removal and refitting of flywheel
j)Renewal of crankshaft front oil seal
k)Removal and refitting of
engine/transmission mountings
Note: It is possible to renew the crankshaft
rear oil seal with the engine in the vehicle, but
this requires the use of special tools, and is a
difficult operation, due to the lack of working
space. For this reason, this operation is
described with the engine removed from the
vehicle.
5Major operations requiring
engine removal
The engine must be removed from the
vehicle to carry out the following operations:
a)Renewal of the crankshaft main bearings
b)Removal and refitting of the crankshaft
c)Renewal of crankshaft rear oil seal
6Method of engine removal
The engine may be removed either on its
own, or together with the transmission. Unless
work is also necessary on the transmission, it
is recommended that the engine is removed
on its own. In either case, the engine or
engine/transmission assembly must be lifted
out through the top of the engine
compartment, using a hoist and lifting tackle.
7Engine - removal and refitting,
(leaving transmission in car)
4
Note: A hoist and lifting tackle will be required
for this operation.If the torque converter is
removed (even partially) from the transmission,
a considerable amount of the fluid inside it will
leak out. To prevent this, when prising the
engine from the transmission and removing it,
be careful to keep the torque converter
pressed firmly into the transmission. If the
transmission is to be removed for some time,
retain the torque converter by bolting a strip of
metal across the bellhousing mating surface.
Removal
1Disconnect the battery negative lead.
2Remove the bonnet (Chapter 11).
3Apply the handbrake, then jack up the front
of the vehicle, and support securely on axle
stands (see “Jacking and Vehicle Support”).
4Drain the cooling system, remove the
radiator and transmission fluid cooler hoses
(automatic models), as described in Chapter 3.
5Drain the engine oil as described in Chapter 1,
remove the oil filter and discard, safely.
6Remove the air cleaner (or air cleaner
cover), the air cleaner trunking, and the air
box from the carburettor or throttle body (as
applicable), referring to Chapter 4A or 4B, if
necessary. On carburettor models,
disconnect the hot air hose from the exhaust
manifold hot air shroud and the air cleaner,
and remove the hose. On automatic models,
disconnect additional wiring, hoses, etc., from
the carburettor, as described in Chapter 4A.
7Remove the alternator, as described in
Chapter 5.
8On models with power steering, remove the
hydraulic pump, as described in Chapter 10.
9Disconnect the brake servo vacuum hose
from the inlet manifold.
10Disconnect the throttle cable from the
throttle lever and the bracket on the
carburettor or inlet manifold, as applicable.
11On carburettor models, disconnect the
coolant hoses from the automatic choke
housing, and disconnect the wiring from the
automatic choke heater and the choke
pull-down solenoid (see illustrations). Also
disconnect the air box vacuum pipe from the
carburettor.
2A•8SOHC engine procedures
2.3 Crankcase ventilation filter removed
from camshaft cover -
1.6 litre engine