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
of the way (see illustration).
3Remove the spacer ring from the end of the
crankshaft (see illustration).
Refitting
4Coat the oil pump mating face of the spacer
ring with sealing compound, then push the
spacer ring onto the end of the crankshaft
until it is seated against the oil pump.
5The timing belt should be renewed, see
Sections 4 and 5, for details.
6Remember also to reconnect the oil cooler
pipes to the oil pump, and tighten the unions.
15Oil cooler - removal and
refitting
3
Removal
1To gain sufficient access to remove the oil
cooler, the radiator must be removed (as
described in Chapter 3). Alternatively, the
front bumper can be removed, as described in
Chapter 11 (see illustration).
2With the appropriate component(s)removed for access, unscrew the oil cooler
pipe unions from the oil cooler. Be prepared
for oil spillage, and plug the open ends of the
pipes, to prevent further oil leakage and dirt
ingress.
3Unscrew the two securing nuts, and
withdraw the oil cooler from its mounting
brackets.
Refitting
4Refitting is a reversal of removal, but on
completion, check and if necessary top-up
the engine oil level, as described in Chapter 1.
2B•10DOHC engine procedures
15.1 Oil cooler viewed through front spoiler. Securing nuts
arrowed14.3 Oil pump securing bolts (arrowed) and crankshaft spacer
ring (A)
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
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
30With the engine removed, the
transmission can be supported by placing a
length of wood between the bellhousing and
the front suspension subframe. Once the
wooden support is in place, remove the trolley
jack from under the transmission.
Refitting
Note: New left and right-hand
engine/transmission mounting-to-body bolts
must be used on refitting.
31Use an M10 x 1.25 bottoming tap to clean
the threads in the torque converters threaded
bosses and ensure that new bolts are
available for reassembly, where applicable.
32Support the transmission with a trolley
jack and remove the length of wood from
between the bellhousing and the subframe.
33Support the engine with the hoist and
lifting tackle, and gently lower it into position
in the engine compartment.
34Mate the engine and transmission
together, ensuring that the transmission
locates on the dowels in the cylinder block,
then refit the three upper
engine-to-transmission bolts.
35Tighten all nuts and bolts to their specified
torque wrench settings. When tightening the
torque converter-to-flexplate bolts to their
specified torque wrench settings, a
commercially available adapter will be
required (see illustration).
36If the clutch is still bolted to the flywheel,
ensure that the weight of the transmission is
not allowed to hang on the input shaft as it is
engaged with the clutch friction disc.
37Refit the four lower
engine-to-transmission bolts, but again do not
fully tighten them at this stage.
38Fit the right-hand engine mounting
bracket to the cylinder block, and tighten the
securing bolts to the specified torque.39Manipulate the engine and transmission
as necessary to enable the right-hand engine
mounting-to-body bolts to be fitted, then fit
new bolts and tighten them to the specified
torque.
40Tighten all the engine-to-transmission
bolts to the specified torque, then disconnect
the lifting tackle and hoist from the engine,
and remove the trolley jack from beneath the
transmission.
41Refit the transmission bellhousing cover
plate.
42Refit the clutch, as described in Chapter
6.
43Refit the front section of the exhaust
system, as described in Chapter 4C.
44Refit the crankshaft pulley using a reversal
of the removal procedure described earlier in
paragraph 22, and tighten the securing bolt(s)
to the specified torque.
45Lower the vehicle to the ground.
46Refit all relevant wires, pipes and hoses,
etc., using a reversal of the removal
procedure described earlier.
47Where applicable, refit the power steering
pump, tension the pump drivebelt, and bleed
the hydraulic fluid circuit, as described in
Chapter 10.
48Refit the alternator and tension the
drivebelt, as described in Chapter 5.
49Refit the air cleaner components, referring
to Chapter 4A or 4B, if necessary. On
carburettor models reconnect the hot air hose
to the exhaust manifold hot air shroud.
50Fit a new oil filter (if not already replaced),
and fill the engine with oil, as described in
Chapter 1.
51Refit the radiator and refill the cooling
system, as described in Chapter 3.
52Refit the bonnet as described in Chapter
11.
53Reconnect the battery negative lead.
54Refer to Section 37
8Engine and transmission -
removal, separation,
reconnection and refitting
4
Note: A hoist and lifting tackle will be required
for this operation
Removal
1Proceed as described in Section 7,
paragraphs 1 to 18 inclusive.
2Working in the engine compartment,
remove the gear selector linkage, as
described in Chapters 7A and 7B, as
appropriate.
3On manual transmission models, remove
the retaining clip, then slide the clutch cable
from the release lever, pushing the release
lever back towards the bulkhead if necessary
to allow the cable to be disconnected. On
automatic models disconnect the selector
cable from the actuating lever, then either
unbolt the cable bracket or release the cable
from the bracket. In either case, pull the cablesupport from the bracket on the transmission
casing, then move the cable and secure to
one side out of the way, taking note of its
routing.
4Disconnect the wiring from the reversing
lamp switch, which is located at the front of
the manual transmission casing, above the
left-hand mounting bracket. On automatic
models, disconnect the transmission wiring
by unplugging the five connector plugs from
the various switches, solenoids and sensors.
Release also the wiring from any clips or ties
securing to the vehicle.
5Where applicable, withdraw the automatic
transmission breather hose from under the
battery bracket. Disconnect the oxygen
sensor wiring if fitted.
6Unscrew the securing sleeve, and
disconnect the speedometer cable from the
transmission.
7Unscrew the retaining nut, and disconnect
the earth strap from the transmission
endplate.
8Make a final check to ensure that all
relevant hoses, pipes, wires etc. have been
disconnected, and that they are positioned
clear of the engine and transmission.
9Proceed as described in Section 7,
paragraphs 19 and 22.
10Disconnect the inboard ends of the
driveshafts from the differential, referring to
the relevant paragraphs of Chapter 8. Be
prepared for oil spillage as the driveshafts are
withdrawn, and plug the apertures in the
differential, to prevent further loss of oil and
dirt ingress. Support the driveshafts by
suspending them with wire or string - do not
allow them to hang down under their own
weight.
11Attach a hoist and lifting gear to the
engine lifting brackets on the cylinder head,
and support the weight of the engine.
12Remove the left-hand transmission
mounting completely by unscrewing the two
bolts securing the rubber mounting to the
vehicle, body, and the three bolts securing the
mounting bracket to the transmission (see
illustration).
13Unbolt the right-hand engine mounting
from the body and from the cylinder block,
and withdraw the mounting bracket.
2A•10SOHC engine procedures
8.12 Left-hand transmission mounting
viewed from underside of vehicle7.35 Commercially-available torque
wrench adapter being used to tighten
torque converter bolts
If a tap is not available, cut
two slots into the threads of
one of the old flywheel bolts
and use the bolt to remove
the locking compound from the
threads.
14Working under the vehicle, unscrew and
remove the two nuts securing the
engine/transmission rear mounting to the front
subframe, and the three bolts securing the
mounting bracket to the transmission, then
withdraw the mounting bracket (see
illustrations).
15Carefully swing the engine/transmission
assembly across the engine compartment as
necessary, to allow the assembly to be lifted
vertically from the vehicle by raising the hoist.
Take care not to damage any of the
surrounding components in the engine
compartment.
Separation
16With the engine/transmission assembly
removed, support the assembly on blocks of
wood positioned on a workbench, or failing
that, on a clean area of the workshop floor.
17Clean away any external dirt using
paraffin or a water-soluble solvent and a stiff
brush.
18Unbolt and remove the transmission
bellhousing cover plate.
19Ensure that both engine and transmission
are adequately supported, then unscrew and
remove the engine-to-transmission bolts.
20Carefully withdraw the transmission from
the engine, ensuring that the weight of the
transmission is not allowed to hang on the
input shaft while it is engaged with the clutch
friction disc. Note that the transmission
locates on dowels positioned in the cylinder
block.
21On automatic models unbolt the
transmission bellhousing cover plate (three
bolts), then use chalk or a felt-tip pen to mark
the relationship of the torque converter to the
flexplate before unbolting the torque
converter. Note: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
transmission off its locating dowels 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. Applying a spanner to the crankshaft
pulley/sprocket bolt, rotate the crankshaft
until the first bolt appears, then use ascrewdriver or similar to jam the flexplate ring
gear teeth to prevent it from rotating as the
bolt is unscrewed. Unscrew each of the three
bolts in turn and remove them.
Reconnection
22Before beginning the refitting operations,
check that the two original bolts that secured
the left-hand transmission rubber mounting to
the vehicle body rotate freely in their threaded
bores in the body. If necessary, re-cut the
threaded bores using an M10 x 1.25 mm tap.
23Where applicable, if the clutch assembly
has been removed from the flywheel, it will
prove easier to refit after the transmission has
been refitted.
24On automatics, if any fluid was spilled from
the torque converter, be careful to refill it as
much as possible. Wipe clean the converter’s
spigot to prevent damage to the transmission’s
input shaft oil seal as the converter is installed,
and ensure that the converter engages
correctly on the fluid pump shaft.
25If the transmission has been renewed, be
careful to flush clean the radiator fluid cooler
passages. Vauxhall recommend the use of
low-pressure compressed air, but this will
require great care to avoid deforming the
radiator.
26Be very careful to ensure that all
components are scrupulously clean, to avoid
the risk of dirt getting into the system.
27Use an M10 x 1.25 bottoming tap to clean
the threads in the torque converters threaded
bosses and ensure that new bolts are
available for reassembly, where applicable.
28Tighten all nuts and bolts to their specified
torque wrench settings.
29Refer also to Section 7, paragraphs 35
and 36.
30Carefully offer the transmission to the
engine until the bellhousing is located on the
dowels in the cylinder block, then refit the
engine-to-transmission bolts, and tighten
them to the specified torque.
31Refit the transmission bellhousing cover
plate.
Refitting
32Working under the vehicle, refit the rear
engine/transmission mounting to the
transmission, using new locking plates under
the bolt heads, and tighten the bolts to the
specified torque.
33Fit the two bolts securing the engine/
transmission rear mounting to the front
subframe, but do not fully tighten at this stage.
34Fit the right-hand engine mounting
bracket to the cylinder block, and tighten the
securing bolts to the specified torque.
35Fit new right-hand engine
mounting-to-body bolts, but do not fully
tighten them at this stage.
36Fit the left-hand transmission mounting
bracket to the transmission, and tighten the
securing bolts to the specified torque.
37Fit new left-hand transmission
mounting-to-body bolts, and tighten them to
the specified torque.
38Tighten the right-hand engine mounting-
to-body bolts and the engine/transmission
rear mounting-to-front subframe bolts to their
specified torques, then remove the lifting
tackle and hoist from the engine.
39Where applicable, the clutch can now be
fitted, and the transmission input shaft can be
pressed into engagement with the splined hub
of the clutch friction disc, (see Chapter 5).
40Reconnect the inboard ends of the
driveshafts to the differential, with reference
to the relevant paragraphs of Chapter 8, and
using new snap rings.
41Refit the front section of the exhaust
system, as described in Chapter 4C.
42Refit the crankshaft pulley, using a
reversal of the removal procedure described
in Section 7, paragraph 22, and tighten the
securing bolt(s) to the specified torque.
43On automatic models, connect the wires
to the various switches, solenoids and
sensors. Replace the transmission breather
hose and oxygen sensor (if fitted).
44Reconnect the transmission earth strap,
and tighten the securing nut.
45Lower the vehicle to the ground.
46Reconnect the speedometer cable to the
transmission, and tighten the securing sleeve.
47Reconnect the reversing lamp wiring.
48On manual transmission models, refit the
clutch cable to the bracket on the
transmission casing, then reconnect the cable
to the release lever, and adjust the cable as
described in Chapter 6. Ensure that the cable
is routed as noted during removal.
49Refit the gear selector linkage, as
described in Chapter 7A, if applicable.
50Proceed as described in Section 7,
paragraphs 41 to 52 inclusive.
51Top-up the transmission oil level, as
described in Chapters 7A and 7B.
52Adjust the selector cable on completion,
and refill the transmission with fluid (see
above).
53Reconnect the battery negative lead.
54Refer to Section 37
SOHC engine procedures 2A•11
8.14B Rear engine/transmission mounting-
to-transmission bolts (arrowed)8.14A Rear engine/transmission
mounting-to-front subframe nuts
2A
If a tap is not available, cut
two slots into the threads of
one of the old flywheel bolts
and use the bolt to remove
the locking compound from the threads.
3
System type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressurised, with remote expansion tank. Coolant pump driven by
timing belt
Coolant
Type/specification (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Lubricants and fluidsin “Weekly checks”
Capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Chapter 1 Specifications
Thermostat
Starts to open at (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92°C
Fully open at (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107°C
Operating temperature (approx.) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80°C
Expansion tank cap
Opening pressure (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.20 to 1.35 bar
Boiling point . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125°C
Cooling fan switch
Switches on at (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100°C
Switches off at (all models) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95°C
Torque wrench settingsNm lbf ft
Coolant pump bolts:
1.4 and 1.6 litre models
(except C16 NZ2), (M6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
C16 NZ2, 1.8 and 2.0 litre models (M8) . . . . . . . . . . . . . . . . . . . . . . . 25 18
Oil pipes to radiator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 16
Outlet to thermostat housing,
C16 NZ2, 1.8 and 2.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 6
Temperature sender . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 7
Temperature sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 8
Thermostat housing to cylinder head:
1.4 and 1.6 litre models (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . 10 7
C16 NZ2, 1.8 and 2.0 litre models . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 11
Chapter 3
Cooling, heating and ventilation systems
Coolant mixture - general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
Coolant pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .11
Cooling fan - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Cooling fan switch - removal and refitting . . . . . . . . . . . . . . . . . . . . .15
Cooling system - draining . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2
Cooling system - filling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
Cooling system - flushing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Expansion tank and coolant level sensor - removal and refitting . . . .13
Facia ventilation nozzles - removal and refitting . . . . . . . . . . . . . . . .19
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1Heater blower motor - removal and refitting . . . . . . . . . . . . . . . . . . .18
Heater control panel - removal and refitting . . . . . . . . . . . . . . . . . . . .16
Heater matrix - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . .17
Radiator (automatic transmission) - removal and refitting . . . . . . . . . .7
Radiator (manual transmission) - removal and refitting . . . . . . . . . . . .6
Radiator - inspection and cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Temperature gauge sender - removal and refitting . . . . . . . . . . . . . .14
Thermostat - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Thermostat - testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
3•1
Specifications Contents
Easy,suitable for
novice with little
experienceFairly easy,suitable
for beginner with
some experienceFairly difficult,
suitable for competent
DIY mechanic
Difficult,suitable for
experienced DIY
mechanicVery difficult,
suitable for expert DIY
or professional
Degrees of difficulty
54321
1General description
Engine cooling is achieved by a
conventional pump-assisted system, in which
the coolant is pressurised. The system
consists of a radiator, a coolant pump driven
by the engine timing belt, an electric cooling
fan, a thermostat, an expansion tank, and
connecting hoses. Hoses also carry coolant to
and from the heater matrix, which provides
heat for the ventilation and heating system.
The system works in the following way.
Cold coolant from one side of the radiator,
which is mounted at the front of the engine
compartment, passes to the coolant pump,
which forces the coolant through the coolant
passages in the cylinder block and cylinder
head. The coolant absorbs heat from the
engine, and then returns to the radiator
through the heater matrix. As the coolant
flows across the radiator it is cooled, and the
cycle is repeated.
Air flows through the radiator, to cool the
coolant as a result of the vehicle’s forward
motion. However, if the coolant temperature
exceeds a given figure, a
temperature-sensitive switch in the radiator
switches on the electric fan, to increase the
airflow through the radiator. The fan only
operates when necessary, with a consequent
reduction in noise and energy consumption.
To reduce the time taken for the engine to
warm up when starting from cold, the
thermostat, located in the cylinder head
outlet, prevents coolant flowing to the radiator
until the temperature has risen sufficiently.
Instead, the outflow from the cylinder head
bypasses the radiator, and is redirected
around the engine. When the temperature
reaches a given figure, the thermostat opens,
to allow coolant to flow to the radiator. The
thermostat is operated by the expansion of a
temperature sensitive wax capsule.
An expansion tank is incorporated in the
system, to allow for coolant expansion. The
system is topped up through a filler cap on
the expansion tank.
Note that later models may be fitted with
self-tensioning spring clamps to secure the
cooling system (including heater) hoses.
These clamps can be released by squeezing
together their free ends using a large pair of
self-grip pliers or similar so that the clamp can
be moved up the hose, clear of the union.
Check that the clamp is securely seated, and
check for leaks on reassembly.
2Cooling system -draining
2
1With the vehicle parked on level ground,
remove the expansion tank filler cap. If the
engine is warm, cover the filler cap with a
thick cloth, and unscrew the cap slowly, to
gradually relieve the system pressure. Take
care to avoid scalding by steam or coolant
escaping from the pressurised system.
2On DOHC models, remove the engine
undershield, with reference to Chapter 11.
3Position a container beneath the radiator
bottom hose connection, then slacken the
hose clip and ease the hose from the radiator
stub. If the hose joint has not been disturbed
for some time, it will be necessary to
manipulate the hose to break the joint. Allow
the coolant to drain into the container.
4As no cylinder block drain plug is fitted, and
the radiator bottom hose may be situated
halfway up the radiator, the system cannot be
drained completely. Care should therefore be
taken when refilling the system to maintain
antifreeze strength.
5If the coolant has been drained for a reason
other than renewal, then provided it is clean
and less than two years old, it can be re-used.
6If the coolant has been drained for renewal,
and is badly contaminated, the coolant
system should be flushed as described in
Section 4. As the system cannot be drained
completely, it is advisable to flush the system
whenever the coolant is renewed, to minimise
the impurities remaining in the system.
3Cooling system -flushing
2
1If coolant renewal has been neglected, or if
the antifreeze mixture has become diluted,
then in time the cooling system will gradually
lose efficiency, as the coolant passages
become restricted due to rust, scale deposits
and other sediment. To restore coolant
system efficiency, it is necessary to flush the
system clean.
2The radiator should be flushed
independently of the engine, to avoid
unnecessary contamination.
3To flush the radiator, disconnect the top
hose at the radiator, then insert a garden hose
into the radiator top inlet. Direct a flow of
clean water through the radiator, and continue
flushing until clean water emerges from the
radiator bottom outlet (the bottom hose
should have been disconnected to drain the
system). If after a reasonable period, the water
still does not run clear, the radiator can be
flushed with a good proprietary cleaning
agent. It is important that the manufacturer’s
instructions are followed carefully. If the
contamination is particularly bad, insert the
hose in the radiator bottom outlet, and flush
the radiator in reverse.
4To flush the engine, continue as follows.
1.4 and 1.6 litre models (except
C16 NZ2)
5Remove the thermostat as described in
Section 9, then temporarily refit the
thermostat cover.
6With the radiator top and bottom hoses
disconnected from the radiator, insert a
garden hose into the radiator bottom hose.
Direct a flow of clean water through the
engine, and continue flushing until clean water
emerges from the radiator top hose.
7On completion of flushing, refit the
thermostat, and reconnect the hoses.
C16 NZ2, 1.8 and 2.0 litre
models
8Remove the thermostat and cover
assembly, as described in Section 9.
9With the radiator bottom hose
disconnected from the radiator, insert a
garden hose into the radiator bottom hose.
Direct a flow of clean water through the
engine, and continue flushing until clean water
emerges from the thermostat housing. It is
advisable to place a sheet of plastic under the
thermostat housing to deflect water away
from the engine and surrounding components
during the flushing process.
10On completion of flushing, refit the
thermostat and cover assembly, reconnect
the hoses and remove the sheet of plastic.
4Cooling system -filling
2
1Before attempting to fill the cooling system,
make sure that all hoses and clips are in good
condition, and that the clips are tight. Note
that an antifreeze mixture must be used all
year round, to prevent corrosion of the alloy
engine components -refer to Section 5.
2On 1.4 and 1.6 litre models (except C16
NZ2), disconnect the wire and unscrew the
coolant temperature sender from the inlet
manifold.
3Remove the expansion tank cap, and fill the
system by slowly pouring the coolant into the
expansion tank to prevent air locks from
forming.
4If the coolant is being renewed, begin by
pouring in a couple of pints of water, followed
by the correct quantity of antifreeze (see
Section 5), then top-up with more water.
5On 1.4 and 1.6 litre models (except C16
NZ2), refit the coolant temperature sender
when coolant free of air bubbles emerges
from the orifice in the inlet manifold.
6Top-up the coolant level to the “COLD” (or
“KALT”) mark on the expansion tank, then refit
the expansion tank cap.
7Start the engine and run it until it reaches
normal operating temperature, then stop the
engine and allow it to cool.
8Check for leaks, particularly around
disturbed components. Check the coolant
3•2Cooling, heating and ventilation systems
When renewing any hoses,
use a little soapy water as a
lubricant, or soften the hose
in hot water. Do not use oil or
grease, as this may attack the rubber.