1988 OPEL CALIBRA gas type

Maintenance - component location 1•5
1
Underbonnet view of a 1989 1.6 L model (16 SV engine)
1 VIN plate
2 Air cleaner casing *
3 Suspension strut top
4 Coolant expansion tank
5 Brake fluid reservoir
6 Fuel pump
7 Steering rack
8 Octane rating plug
9 Washer fluid reservoir
10 Battery
11 Ignition coil
12 Distributor (Bosch type)
13 Cooling fan motor
14 Engine oil level dipstick
15 Oil filter
16 Oil filler cap
* Refer to Chapter 4A for
alternative type
Underbonnet view of a 1991 model Cavalier 1.6 L (C16 NZ engine)
1 Air cleaner casing
2 Suspension strut top
3 Coolant expansion tank
4 Brake fluid reservoir
5 Air box
6 Exhaust gas recirculation valve
7 Steering gear
8 Octane coding plug
9 Washer fluid reservoir
10 Battery
11 Ignition coil
12 Distributor
13 Cooling fan motor
14 Engine oil level dipstick
15 Engine oil filter
16 Oxygen sensor
17 Engine oil filler cap

3When refitting the distributor cap, check
that the ends of the HT leads are fitted
securely to the cap, plugs and coil. Also make
sure that the spring-tensioned carbon brush
in the centre of the distributor cap moves
freely, and that the HT segments are not worn
excessively.
4Inspect the electrical and vacuum
connections of the ignition/engine
management systems, and make sure that
they are clean and secure.
32Clutch cable check
2
Check the clutch cable adjustment, as
described in Chapter 6.
Check also, the condition of the cable.
Inspect the cable strands for fraying, and
ensure that the cable is correctly routed, to
avoid chafing against surrounding
components. Renew the cable, as described
in Chapter 6, if excessive wear or damage is
evident.
33Manual transmission fluid
check
2
Note:Models built after 1994 it is no longer
necessary to check levels.
1Ensure that the vehicle is on level ground.
2Unscrew the transmission oil level plug,
which is located in the rear left of the
differential housing on F10 and F13
transmissions, and in the rear right of the
differential housing on F16 and F20
transmissions (see illustrations). The oil level
should be up to the bottom of the level plug
orifice.
3If necessary, top-up the oil level through the
breather/filler orifice in the gear selector
cover. Unscrew the breather/filler plug, and
top-up with the specified grade of oil, until oil
just begins to run from the level plug orifice.
Refit the level plug and the breather/filler plug
on completion (see illustrations).
4Renewal of the transmission oil is not
specified by the manufacturers, and no drain
plug is provided. If it is desired to renew the oil
as a precaution, the oil may be drained by
removing the differential cover plate. Use a
new gasket when refitting the cover plate. Fillthe transmission through the breather/filler
orifice, as described previously in this
Section.
5Periodically inspect the transmission for oil
leaks, and check the gear selector linkage
components for wear and smooth operation.
34Automatic transmission
check
2
1Carry out a thorough road test, ensuring
that all gearchanges occur smoothly, without
snatching and with no increase in engine
speed between changes.
2Check the operation of the kickdown.
Check that all gear positions can be engaged
at the appropriate movement of the selector
lever and with the vehicle at rest, check that
the operation of the parking pawl in position
“P” prevents it from being moved. Ensure that
the starter motor will work only with the
selector lever in positions “P” or “N”, and thatthe reversing lamps light only when position
“R” is selected.
3The manufacturer’s schedule calls for a
regular check of the electrical control system
using the special Vauxhall test equipment;
owners will have to have this check carried
out by a Vauxhall dealer.
4Periodically inspect the transmission
casing, checking all joint surfaces and seals
for signs of fluid leaks. If any are found, the
fault must be rectified immediately.
5Check also that the transmission breather
hose (under the battery mounting bracket) is
clear and not blocked, kinked or twisted.
35Brake shoe check
2
Note:On models fitted with rear brake pads,
the handbrake operates brake shoes that are
located inside the rear brake discs.
Refer to Chapter 9, for details.
Every 18 000 miles or 24 months 1•15
33.3A Transmission breather/filler plug
(arrowed) - F16 type transmission33.3B Topping-up the transmission oil
level - F13 type transmission
33.2B Transmission oil level plug
(arrowed) - F16 type transmission (viewed
from below, with driveshaft removed)33.2A Transmission oil level plug
(arrowed) - F13 type transmission (viewed
from above)
1

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.

Oil pick-up pipe bracket to cylinder block . . . . . . . . . . . . . . . . . . . . . . .64
Oil pick-up pipe to oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Oil pipes to radiator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2216
Oil pressure switch to oil pump:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . .3022
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Oil pressure relief valve to oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Oil pump cover to oil pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Oil pump to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Oxygen sensor to exhaust manifold . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Power steering pump bracket to support:
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1813
Power steering pump to support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Right engine mounting to subframe . . . . . . . . . . . . . . . . . . . . . . . . . . . .6548
Shackle to alternator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Spark plugs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Starter to cylinder block (M10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4533
Starter to cylinder block (M12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6044
Sump:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . . .86
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1511
Sump drain plug . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5541
Support to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3526
Temperature sender to cylinder head . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
Thermostat housing:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . . .107
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1511
Timing belt tensioner to oil pump:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . . .5541
Timing belt cover to oil pump/camshaft housing:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . . .129
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64
Timing belt drive gear to crankshaft:
C16 NZ2, 1.8 and 2.0 litre:
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13096
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by between 40º to 50º
Transmission to engine (M10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4533
Transmission to engine (M12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6044
1General description
General
The engine is of four-cylinder, in-line single
or double overhead camshaft type (depending
on model), mounted transversely at the front
of the vehicle.
The crankshaft runs in five shell-type
bearings, and the centre bearing incorporates
a thrust bearing shell to control crankshaft
endfloat.
The connecting rods are attached to the
crankshaft by horizontally split shell-type
big-end bearings. On single overhead
camshaft (SOHC) models, the pistons are
attached to the connecting rods by gudgeon
pins, which are an interference fit in the
connecting rod small-end bore. The
aluminium alloy pistons are fitted with three
piston rings: two compression rings and an oil
control ring.
The camshaft on SOHC engines is driven
from the crankshaft by a toothed composite
rubber belt. Each cylinder has two valves (oneinlet and one exhaust), operated through
rocker arms that are supported at their pivot
ends by hydraulic self-adjusting valve lifters
(tappets).
The inlet and exhaust valves are each
closed by a single valve spring, and operate in
guides pressed into the cylinder head.
A gear-type oil pump is located in a housing
attached to the front of the cylinder block, and
is driven directly from the crankshaft. A
full-flow type oil filter is fitted.
The distributor is driven directly from the
end of the camshaft. On carburettor models,
the mechanical fuel pump is operated from
the front end of the camshaft. The coolant
pump is located at the front of the cylinder
block, and is driven by the timing belt.
Chapter 2A describes the SOHC engine
repair procedures. Many repairs and specifi-
cations to the DOHC engine are similar to the
2.0 litre SOHC. However where they differ,
details can be found in Chapter 2B.
Engine identification codes -
general
Before ordering spare parts, or carrying out
any repair or overhaul operations on the
engine, it is essential to identify the exactengine type being worked on. Later engines,
although outwardly similar in appearance,
often have significant differences in repair
procedures, even though they may be of the
same displacement and model year.
The following sub-Sections in this Chapter
are mainly specific to engine type, as will be
noted from the sub-Section headings. Check
the engine identification code first, which is
located on a horizontal surface on the exhaust
manifold side of the cylinder block, at the
distributor end. On later engines, the code is
on the cylinder block-to-transmission flange,
next to the engine oil dipstick.
2Crankcase ventilation
system - description and
maintenance
2
Description
1A crankcase ventilation system is fitted to
all models, but the systems differ in detail
depending on the model concerned.
2Oil fumes and blow-by gases (combustion
gases that have passed by the piston rings)
are drawn from the crankcase into the area of
SOHC engine procedures 2A•7
2A

Inspection
7With the camshaft removed, examine the
bearings in the camshaft housing for signs of
obvious wear or pitting. If evident, a new
camshaft housing will probably be required.
8The camshaft itself should show no marks
or scoring on the journal or cam lobe
surfaces. If evident, renew the camshaft. Note
that if the camshaft is renewed, all the rocker
arms should also be renewed.
9Check the camshaft thrustplate for signs of
wear or grooves, and renew if evident.
10It is advisable to renew the camshaft front
oil seal as a matter of course if the camshaft
has been removed. Prise out the old seal
using a screwdriver (see illustration).
Reassembly
11Carefully drive in the new front seal until it
is flush with the housing, using a socket or
tube. On C 16 NZ2, 1.8 and 2.0 litre models,
fit a new camshaft rear oil seal. Replace the
distributor O-ring on other models (see
illustrations).
12Begin reassembly by liberally oiling the
bearings in the housing and the oil seal lip.
Carefully insert the camshaft into the housing
from the distributor end, taking care to avoid
damage to the bearings.
13Refit the thrustplate, and tighten the
securing bolts (see illustration). Check the
camshaft endfloat by inserting a feeler blade
between the thrustplate and the camshaft end
flange. If the endfloat exceeds that specified,
renew the thrustplate.14Where applicable, refit the fuel pump,
referring to Chapter 4, if necessary.
15Refit the distributor as described in
Chapter 5.
16Refit the camshaft housing, as described
in Section 18.
17If a new camshaft has been fitted, it is
important to observe the following running-in
schedule (unless otherwise specified by the
manufacturer) immediately after initially
starting the engine:
One minute at 2000 rpm
One minute at 1500 rpm
One minute at 3000 rpm
One minute at 2000 rpm
18Change the engine oil (but not the filter,
unless due) approximately 600 miles (1000
km) after fitting a new camshaft.19Camshafts, “undersize” C16
NZ2, 1.8 and 2.0 litre engines
- general
General
1The camshafts and camshaft housings for
these engines are sorted on production into
one of two size groups; standard and 0.10
mm “undersize”. Note that this is not intended
to provide replacements for worn engines, but
is to allow for production tolerances; either
may be fitted to new engines.
2“Undersize” components are marked with a
spot of violet-coloured paint, that on the
camshaft housing being applied on top at the
timing belt end.3Whenever the camshaft or its housing are
to be renewed, check (by direct
measurement, if necessary) whether they are
standard or undersize and ensure that only
matching items are obtained for reassembly.
20Cylinder 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 and a new cylinder head gasket
must be used on refitting and sealer will be
required when refitting the camshaft housing.
The torque settings stated 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.
3Disconnect the exhaust downpipe from the
manifold, referring to Chapter 4C.
4The cylinder head can be removed
complete with the manifolds, or the manifolds
can be detached from the cylinder head
before removal, with reference to the relevant
Sections of Chapter 4A, 4B or 4C. If no work
is to be carried out on the inlet manifold, it can
be unbolted from the cylinder head and
SOHC engine procedures 2A•19
18.10 Prising out the camshaft front oil
seal - 2.0 litre engine
18.13 Tightening a camshaft thrustplate
securing bolt - 2.0 litre engine18.11B Fitting a new camshaft rear oil seal
- 2.0 litre engine18.11A Fitting a new camshaft front oil
seal using a special tool - 2.0 litre engine
18.6 Withdrawing the camshaft from the
housing - 2.0 litre engine18.5 Removing the camshaft thrustplate -
2.0 litre engine
2A

40Refit the camshaft sprocket and the
timing belt and tension the timing belt as
described in Section 11.
41Where applicable, refit the manifolds to
the cylinder head, with reference to Chapter
4A, 4B or 4C, using new gaskets.
42Reconnect the exhaust downpipe to the
manifold, using a new gasket, referring to
Chapter 4C, if necessary.
43Refit the upper alternator mounting to the
inlet manifold, then adjust the alternator
drivebelt tension, as described in Chapter 5.
44Refill the cooling system, as described in
Chapter 3.
45On completion, check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
46When the engine is started, check for
signs of leaks.
47Once the engine has reached normal
operating temperature, check and if
necessary adjust the idle speed (where
applicable) and the mixture (where
applicable), with reference to Chapter 4A or
4B.
21Cylinder head - removal and
refitting (engine removed)
4
Note: New cylinder head bolts and a new
cylinder head gasket must be used on
refitting, and sealer will be required when
refitting the camshaft housing.
The torque settings stated 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 manifolds, or the manifolds
can be detached from the cylinder head
before removal, with reference Chapter 4A,
4B or 4C.
2Remove the timing belt and the camshaft
sprocket, as described in Section 11.
3Unscrew the two upper rear timing belt
cover securing bolts from the camshaft
housing (see illustration).4Disconnect the HT leads from the spark
plugs, labelling them if necessary to aid
refitting, and remove the distributor cap
referring to Chapter 5.
5If not already done, disconnect the stub
hose that connects the crankcase breather
tube to the camshaft housing. If applicable,
unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
6Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
Refitting
7Proceed as described in Section 21,
paragraphs 23 to 41 inclusive, but in addition
note the following.
8On completion check that all relevant
hoses, pipes and wires, etc., have been
reconnected.
22Cylinder head -dismantling
and reassembly
4
Note: A valve spring compressor tool will be
required for this operation. New valve stem oil
seals must be used on reassembly
Dismantling
1With the cylinder head removed as
described in Section 21, clean away all
external dirt.
2If not already done, remove the thermostat
housing, and on 1.4 and 1.6 litre models, thethermostat, as described in Chapter 3.
Remove the manifolds as described in
Chapter 4A, 4B or 4C. Remove the spark
plugs if not already done.
3To remove a valve, fit a valve spring
compressor tool. Ensure that the arms of the
compressor tool are securely positioned on
the head of the valve and the spring cap (see
illustration).
4Compress the valve spring to relieve the
pressure of the spring cap acting on the
collets. If the spring cap sticks on the valve
stem, support the compressor tool and give
the end a light tap with a hammer to help free
the spring cap.
5Extract the two split collets, then slowly
release the compressor tool.
6Remove the spring cap, spring, valve stem
oil seal, and the spring seat, then withdraw
the valve.
2A•22SOHC engine procedures
20.36 Fit new cylinder head bolts, ensuring
that the washers are in place20.37B Tighten the cylinder head bolts to
the specified torque . . .
22.3 Valve spring compressor tool fitted to
No 1 exhaust valve - 2.0 litre engine21.3 Upper rear timing belt cover securing
bolts (arrowed) - 1.6 litre engine
20.37C . . .then through the specified
angle - 2.0 litre engine
20.37A Cylinder head bolt tightening
sequence - SOHC engines

MOTTest Checks REF•11
MExamine the handbrake mechanism,
checking for frayed or broken cables,
excessive corrosion, or wear or insecurity of
the linkage. Check that the mechanism works
on each relevant wheel, and releases fully,
without binding.
MIt is not possible to test brake efficiency
without special equipment, but a road test can
be carried out later to check that the vehicle
pulls up in a straight line.
Fuel and exhaust systems
MInspect the fuel tank (including the filler
cap), fuel pipes, hoses and unions. All
components must be secure and free from
leaks.
MExamine the exhaust system over its entire
length, checking for any damaged, broken or
missing mountings, security of the retaining
clamps and rust or corrosion.
Wheels and tyres
MExamine the sidewalls and tread area of
each tyre in turn. Check for cuts, tears, lumps,
bulges, separation of the tread, and exposure
of the ply or cord due to wear or damage.
Check that the tyre bead is correctly seated
on the wheel rim, that the valve is sound andproperly seated, and that the wheel is not
distorted or damaged.
MCheck that the tyres are of the correct size
for the vehicle, that they are of the same size
and type on each axle, and that the pressures
are correct.
MCheck the tyre tread depth. The legal
minimum at the time of writing is 1.6 mm over
at least three-quarters of the tread width.
Abnormal tread wear may indicate incorrect
front wheel alignment.
Body corrosion
MCheck the condition of the entire vehicle
structure for signs of corrosion in load-bearing
areas. (These include chassis box sections,
side sills, cross-members, pillars, and all
suspension, steering, braking system and
seat belt mountings and anchorages.) Any
corrosion which has seriously reduced the
thickness of a load-bearing area is likely to
cause the vehicle to fail. In this case
professional repairs are likely to be needed.
MDamage or corrosion which causes sharp
or otherwise dangerous edges to be exposed
will also cause the vehicle to fail.
Petrol models
MHave the engine at normal operating
temperature, and make sure that it is in good
tune (ignition system in good order, air filter
element clean, etc).
MBefore any measurements are carried out,
raise the engine speed to around 2500 rpm,
and hold it at this speed for 20 seconds. Allowthe engine speed to return to idle, and watch
for smoke emissions from the exhaust
tailpipe. If the idle speed is obviously much
too high, or if dense blue or clearly-visible
black smoke comes from the tailpipe for more
than 5 seconds, the vehicle will fail. As a rule
of thumb, blue smoke signifies oil being burnt
(engine wear) while black smoke signifies
unburnt fuel (dirty air cleaner element, or other
carburettor or fuel system fault).
MAn exhaust gas analyser capable of
measuring carbon monoxide (CO) and
hydrocarbons (HC) is now needed. If such an
instrument cannot be hired or borrowed, a
local garage may agree to perform the check
for a small fee.
CO emissions (mixture)
MAt the time of writing, the maximum CO
level at idle is 3.5% for vehicles first used after
August 1986 and 4.5% for older vehicles.
From January 1996 a much tighter limit
(around 0.5%) applies to catalyst-equipped
vehicles first used from August 1992. If the
CO level cannot be reduced far enough to
pass the test (and the fuel and ignition
systems are otherwise in good condition) then
the carburettor is badly worn, or there is some
problem in the fuel injection system or
catalytic converter (as applicable).
HC emissionsMWith the CO emissions within limits, HC
emissions must be no more than 1200 ppm
(parts per million). If the vehicle fails this test
at idle, it can be re-tested at around 2000 rpm;
if the HC level is then 1200 ppm or less, this
counts as a pass.
MExcessive HC emissions can be caused by
oil being burnt, but they are more likely to be
due to unburnt fuel.
Diesel models
MThe only emission test applicable to Diesel
engines is the measuring of exhaust smoke
density. The test involves accelerating the
engine several times to its maximum
unloaded speed.
Note: It is of the utmost importance that the
engine timing belt is in good condition before
the test is carried out.
M
Excessive smoke can be caused by a dirty
air cleaner element. Otherwise, professional
advice may be needed to find the cause.
4Checks carried out on
YOUR VEHICLE’S EXHAUST
EMISSION SYSTEM
REF