2A
General
Type
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Four-cylinder, in-line, water-cooled, transversely mounted at front of
vehicle. Single belt-driven overhead camshaft, acting on hydraulic
valve lifters
Manufacturer’s engine codes:
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 litre (1389 cc)
16 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc)
X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) ‘Ecotec’ type engine
C16 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) + catalyst
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.6 litre (1598 cc) + catalyst
18 SV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 litre (1796 cc)
C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 litre (1796 cc) + catalyst
20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc)
20 SEH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc) + early SRi
C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.0 litre (1998 cc) + catalyst
Pistons:Bore (mm) Stroke (mm)
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77.6 73.4
16 SV, C16 SV, C16 NZ and X16 SZ . . . . . . . . . . . . . . . . . . . . . . . . . 79.0 81.5
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80.0 79.5
18 SV and C18 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84.8 79.5
20 NE, 20 SEH and C20 NE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86.0 86.0
Chapter 2 Part A:
SOHC engine procedures
Camshaft front oil seal - removal and refitting . . . . . . . . . . . . . . . . . .15
Camshaft housing and camshaft - general . . . . . . . . . . . . . . . . . . . .17
Camshaft housing and camshaft - dismantling, inspection and
reassembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
Camshaft rear oil seal - removal and refitting . . . . . . . . . . . . . . . . . . .16
Camshafts, “undersize” C16 NZ2, 1.8 and 2.0 litre engines -
general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Compression test - description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3
Crankcase ventilation system - description and maintenance . . . . . . .2
Crankshaft and bearings - examination . . . . . . . . . . . . . . . . . . . . . . .35
Crankshaft and bearings - removal and refitting . . . . . . . . . . . . . . . .34
Crankshaft front oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Crankshaft rear oil seal - renewal . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
Cylinder block and bores - examination and renovation . . . . . . . . . .36
Cylinder head - dismantling and reassembly . . . . . . . . . . . . . . . . . . .22
Cylinder head - inspection and renovation . . . . . . . . . . . . . . . . . . . . .23
Cylinder head - removal and refitting (engine in vehicle) . . . . . . . . . .20
Cylinder head - removal and refitting (engine removed) . . . . . . . . . . .21
Engine - removal and refitting (leaving transmission in car) . . . . . . . . .7
Engine and transmission mountings - renewal . . . . . . . . . . . . . . . . . . .9
Engine and transmission - removal, separation, reconnection and
refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
Engine oil and filter - renewal . . . . . . . . . . . . . . . . . . . . .See Chapter 1Engine dismantling and reassembly - general . . . . . . . . . . . . . . . . . .10
Examination and renovation - general . . . . . . . . . . . . . . . . . . . . . . . .37
Flexplate (automatic transmission) - removal and refitting . . . . . . . . .26
Flywheel - removal, inspection and refitting . . . . . . . . . . . . . . . . . . . .25
General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1
Hydraulic valve lifters - inspection . . . . . . . . . . . . . . . . . . . . . . . . . . .24
Initial start-up after major overhaul or repair . . . . . . . . . . . . . . . . . . .38
Major operations possible with the engine in the vehicle . . . . . . . . . . .4
Major operations requiring engine removal . . . . . . . . . . . . . . . . . . . . .5
Method of engine removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
Oil pump - dismantling, inspection and reassembly . . . . . . . . . . . . .31
Oil pump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
Pistons and connecting rods - examination and renovation . . . . . . .33
Pistons and connecting rods - removal and refitting . . . . . . . . . . . . .32
Sump - removal and refitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Timing belt and sprockets (without automatic tensioner) - removal,
refitting and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
Timing belt and tensioner 1.4 and 1.6 models (not C16 NZ2) - removal,
refitting and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
Timing belt and tensioner C16 NZ2, 1.8 and 2.0 litre - removal, refitting
and adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
Timing belt cover aperture, 1.4 and 1.6 models - general . . . . . . . . .13
2A•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
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.
9The crankshaft pulley must now be
removed. On 1.4 and 1.6 litre engines (except
C 16 NZ2), the pulley is secured by a single
bolt, which also secures the crankshaft
sprocket. On C 16 NZ2, 1.8 and 2.0 litre
engines, the pulley is secured by four bolts,
which must be unscrewed using an Allen key
or hexagon bit. On manual transmission
models, if the engine is in the vehicle, the
crankshaft can be prevented from turning by
having an assistant engage first gear and
depress the brake pedal. Alternatively, the
flywheel ring gear teeth can be jammed using
a large screwdriver or similar tool.
10With the crankshaft pulley removed, the
timing belt can be withdrawn.
11If desired, the sprockets and the rear
timing belt cover can be removed as follows,
otherwise go on to paragraph 23.
12To remove the camshaft sprocket, firstdisconnect the breather hose(s) from the
camshaft cover, then unscrew the securing
bolts noting the locations of the HT lead
brackets and any other wiring brackets, and
remove the camshaft cover.
13Recover the gasket. Prevent the camshaft
from turning by holding it with a spanner on
the flats provided between No’s 3 and 4
camshaft lobes, and unscrew the camshaft
sprocket bolt.
14Withdraw the sprocket from the end of the
camshaft.
15To remove the crankshaft sprocket on 1.4
and 1.6 litre engines (except C 16 NZ2), if
necessary, remove the lower securing bolts
from the main rear timing belt cover and use
two large screwdrivers behind the cover to
lever off the sprocket. Remove the Woodruff
key if it is loose.
16To remove the crankshaft sprocket on C
16 NZ2, 1.8 and 2.0 litre engines, it will benecessary to prevent the crankshaft from
turning, as described in paragraph 9. Take
care when unscrewing the sprocket bolt, as it
is very tight. If necessary, use a two-legged
puller to remove the sprocket. Recover the
Woodruff key and the thrustwasher from the
end of the crankshaft.
17To remove the main rear timing belt cover
on C 16 NZ2, 1.8 and 2.0 litre models
disconnect the TDC sensor wiring plug and
unclip the wiring from the belt cover. Then
unscrew the two upper securing bolts and the
lower securing bolt(s) (one in the case of C 16
NZ2, 1.8 and 2.0 litre engines, two on other
SOHC engines). Withdraw the cover,
manipulating it from the smaller rear belt
cover on the coolant pump (see illustrations).
18If desired, the smaller rear belt cover can
be removed from the coolant pump, after
unscrewing the securing bolt (see
illustration), by rotating it to disengage it from
the retaining flange on the pump.
Refitting
19Refit the rear timing belt cover(s) using a
reversal of the removal procedure, and
ensuring that the main cover engages correctly
with the smaller cover on the coolant pump.
20On C 16 NZ2, 1.8 and 2.0 litre engines,
refit the thrustwasher and the Woodruff key to
the end of the crankshaft. Then refit the
crankshaft sprocket, and tighten the securing
bolt to the specified torque in the two stages
given in the Specifications. Ensure that the
washer is in place under the bolt head, and
prevent the crankshaft from turning as during
removal (see illustrations).
2A•14SOHC engine procedures
11.17A Loosening the main rear timing
belt cover lower securing bolt -
2.0 litre engine11.18 Unscrewing the coolant pump rear
belt cover securing bolt - 2.0 litre engine
11.20E Tighten the bolt to the specified
torque . . .11.20D . . .and the washer and bolt11.20C . . .the crankshaft sprocket . . .
11.20B . . . the Woodruff key . . .11.20A Refit the thrustwasher . . .
11.17B Main rear timing belt cover lower
securing bolts (arrowed) - 1.6 SV engine
21On 1.4 and 1.6 litre engines (except C 16
NZ2), refit the Woodruff key to the end of the
crankshaft where applicable. Then refit the
crankshaft sprocket with the flange and
locating lug for the crankshaft pulley
outermost (see illustration).
22Refit the camshaft sprocket, ensuring that
the locating pin on the end of the camshaft
engages with the hole in the sprocket, and
tighten the securing bolt to the specified
torque. Prevent the camshaft from turning as
during removal. Check the condition of the
camshaft cover gasket and renew if
necessary, then refit the camshaft cover,
ensuring that the HT lead brackets and any
other wiring bracket are correctly located, and
reconnect the breather hose(s) (see
illustrations).
23Temporarily refit the crankshaft pulley and
ensure that the crankshaft pulley andcamshaft sprocket timing marks are still
aligned as described in paragraph 7, then refit
the timing belt around the sprockets (see
illustration), starting at the crankshaft
sprocket.
24Refit the crankshaft pulley, and tighten the
securing bolt(s) to the specified torque (see
illustrations). If necessary, prevent the
crankshaft from turning as during removal.
25Adjust the timing belt tension, as
described in Section 11.
26On 1.6 litre models with power steering,
refit the power steering pump, as described in
Chapter 10.
27Refit the outer timing belt covers, and on
C 16 NZ2, 1.8 and 2.0 litre models, reconnect
the temperature gauge sender wiring.
28Refit the alternator drivebelt and adjust
the drivebelt tension, as described in Chapter
5.29On C 16 NZ2, 1.8 and 2.0 litre models
with power steering, refit the power steering
pump drivebelt and adjust the drivebelt
tension, as described in Chapters 1 and 10.
30Reconnect the battery negative lead.
Adjustment
Note: The manufacturers specify the use of a
special gauge Vauxhall tool No KM-510-A for
checking the timing belt tension. If access to a
gauge cannot be obtained it is strongly
recommended that the vehicle is taken to a
Vauxhall dealer to have the belt tension
checked at the earliest opportunity
31The tension of a used timing belt should
be checked with the engine at normal
operating temperature. The tension of a new
timing belt should be checked with the engine
cold.
SOHC engine procedures 2A•15
11.22A Refit the camshaft sprocket . . .
11.24B Tightening a crankshaft pulley
securing bolt - 2.0 litre engine11.24A Refitting the crankshaft pulley -
1.6 litre engine11.23 Refitting the timing belt -
2.0 litre engine
11.22D . . . fit the cover and tighten the
bolts. Note position of HT lead brackets11.22C Fit the camshaft cover gasket . . .11.22B . . . and tighten the securing bolt to
the specified torque - 2.0 litre engine
11.21 Crankshaft sprocket fits with flange
and pulley locating lug outermost -
1.6 litre engine11.20F . . .then through the specified angle
- 2.0 litre engine
2A
8Turn the crankshaft through two complete
revolutions in the normal direction of rotation,
and check that with the crankshaft pulley TDC
mark aligned with the pointer on the rear
timing belt cover. The TDC mark on the
camshaft sprocket is still aligned with the
notch in the timing belt rear cover. Slacken
the automatic tensioner securing bolt again
and move the tensioner arm clockwise, until
the tensioner pointer is aligned with the notch
in the tensioner bracket. In the first few hours
of operation a new belt will be subjected to
‘settling-in’, (known as the running-in
procedure). If you are refitting a used belt (one
that has been ‘run-in’), align the pointer to
approximately 4 mm to the left of the notch
(see illustration).
9Tighten the tensioner securing bolt
securely. Turn the crankshaft through one
complete revolution, in the normal direction of
rotation, and check that the crankshaft and
camshaft timing marks still align. Then refit
the remainder of the components as
described in Section 12.
10With the timing belt adjustment set in this
way, correct tension will always be maintained
by the automatic tensioner and no further
checking or adjustment will be necessary.
15Camshaft front oil seal -
removal and refitting
3
Removal
1The camshaft front oil seal may be renewed
with the engine in the vehicle without
removing the camshaft as follows.
2Remove the timing belt and the camshaft
sprocket, as described in Section 11.
3Punch or drill a small hole in the centre of
the now-exposed oil seal. Screw in a
self-tapping screw, and pull on the screw with
pliers to extract the seal.
Refitting
4Clean the oil seal seat with a wooden or
plastic scraper.
5Grease the lips of the new seal, and drive it
into position until it is flush with the housing,
using a socket or tube. Take care not to
damage the seal lips during fitting.
6Refit the camshaft sprocket and the timing
belt and tension the timing belt as described
in Section 11.
16Camshaft rear oil seal -
removal and refitting
3
Removal
1The camshaft rear oil seal may be renewed
with the engine in the vehicle without
removing the camshaft as follows.
2Remove the distributor as described in
Chapter 53On 1.4 and 1.6 litre models (except C16
NZ2), the seal takes the form of an O-ring on
the rear of the distributor body. Prise off the
old O-ring carefully, using a screwdriver.
4On C16 NZ2, 1.8 and 2.0 litre models, prise
the seal from the camshaft housing
Refitting
5 On 1.4 and 1.6 litre models (except C16
NZ2), fit the new O-ring, and refit the
distributor as described in Chapter 5.
6On C16 NZ2, 1.8 and 2.0 litre models, fit the
new seal so that it is flush with the end of the
housing, then refit the distributor components
as described in Chapter 5.
17Camshaft housing and
camshaft -general
Note: The engine must be cold when
removing the camshaft housing. Do not
remove the camshaft housing from a hot
engine. New cylinder head bolts must be used
on refitting and sealer will be required when
refitting the camshaft housing. Also see
paragraph 3 before starting work:
General
1The camshaft can only be removed without
disturbing the housing, if a special tool is
available to depress the cam followers whilst
the camshaft is withdrawn.2If such a tool is available, the camshaft can
be removed, after removing the timing belt
and camshaft sprocket as described in
Section 11.
3If the special tool is not available, the
camshaft housing must be removed. Since
the cylinder head bolts must be removed, it is
strongly recommended that a new cylinder
head gasket is fitted. If the gasket is not
renewed, and it “blows” on reassembly, the
cylinder head will have to be removed to
renew the gasket, and another new set of
bolts will have to be obtained for refitting. You
have been warned!
4Removal and refitting of the camshaft
housing is described in Section 18, along with
cylinder head removal and refitting. If it is
decided not to disturb the cylinder head, the
relevant paragraphs referring specifically to
cylinder head removal and refitting can be
ignored.
5Removal of the camshaft from the housing
is described in Section 18.
18Camshaft housing and
camshaft - dismantling,
inspection and reassembly
4
Dismantling
1With the camshaft housing removed from
the cylinder head as described in Section 18,
continue as follows.
2Remove the distributor and it’s
components as described in Chapter 5 and
on C 16 NZ2, 1.8 and 2.0 litre, carefully prise
out the camshaft rear oil seal.
3On carburettor models, remove the fuel
pump, referring to Chapter 4A, if necessary.
4Working at the distributor end of the
camshaft, unscrew the two camshaft
thrustplate securing bolts, using an Allen key
or hexagon bit (see illustration).
5Withdraw the thrustplate, noting which way
round it is fitted (see illustration).
6Carefully withdraw the camshaft from the
distributor end of the camshaft housing,
taking care not to damage the bearing
journals (see illustration).
2A•18SOHC engine procedures
14.8 Timing belt adjustment
1 Alignment for new belts
2 Alignment for ‘run-in’ belts (gap is
approximately 4 mm to the left of centre)
18.4 Camshaft thrustplate and
securing bolts -
1.6 litre engine
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 manifolds, disconnect all
relevant hoses, pipes and wiring from the inlet
manifold and associated components,
referring to Chapter 4A or 4B. On carburettor
models, disconnect the hot air hose from the
shroud on the exhaust 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 15.
7Disconnect the air cleaner trunking from the
air box on the carburettor or throttle body, or
directly from the throttle body (as applicable),
and disconnect the camshaft cover breather
hose that runs to the carburettor or throttle
body (as applicable), (see illustration).
8On C 16 NZ2, 1.8 and 2.0 litre models,
disconnect the smaller coolant hose from the
top of the thermostat housing.
9On 1.6 litre models (except C 16 NZ2),
disconnect the breather hose (which runs
from the camshaft cover to the inlet manifold)
at the camshaft cover.
10On fuel injection models, unbolt the two
wiring harnesses earth leads from the
camshaft housing (see illustration).
11On 1.4 and 1.6 litre models (except C 16
NZ2), disconnect the stub hose that connects
the crankcase breather tube to the rear of thecamshaft housing (see illustration).
12Loosen the alternator mountings, referring
to Chapter 5, then unbolt the upper alternator
mounting from the inlet manifold.
13Make a final check to ensure that all
necessary hoses, pipes and wires have been
disconnected, then unscrew the securing
nuts, noting the location of the engine lifting
bracket, 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.
14Recover the manifold gasket from the
cylinder head.
15If desired, remove the exhaust manifold,
with reference to Chapter 4C.
16Remove the timing belt and the camshaft
sprocket, as described in Section 11.
17Unscrew the two upper rear timing belt
cover securing bolts from the camshaft
housing.
18Disconnect the HT leads from the spark
plugs and the coil, labelling them if necessary
to aid refitting, and remove the distributor
cap, referring to Chapter 5. Where applicable,
disconnect the distributor wiring plug.
19If 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 (see illustrations).
20Disconnect the coolant hoses from the
thermostat housing.21On carburettor models, disconnect the fuel
hoses from the fuel pump. Be prepared for fuel
spillage, and plug the open ends of the hoses,
to prevent further fuel loss and dirt ingress.
22Make a final check to ensure that all
relevant hoses, pipes and wires, etc., have
been disconnected.
23Working from the outside inwards in a
spiral pattern as shown (see illustration),
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.
24Lift the camshaft housing from the
cylinder head (see illustration). If necessary,
tap the housing gently with a soft-faced mallet
to free it from the cylinder head, but do not
lever at the mating faces. Note that the
camshaft housing is located on dowels.
25Lift the rocker arms and their thrust pads
from the cylinder head, keeping them in order
so that they can be refitted in their original
positions (see illustrations).
26Lift the hydraulic valve lifters from the
cylinder head, and place them upright in an oil
bath until they are to be refitted (see
illustration). Ensure that the depth of oil is
sufficient to fully cover the valve lifters, and
keep the lifters in order, so that they can be
refitted in their original positions.
27Lift the cylinder head from the cylinder
block (see illustration). 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.
2A•20SOHC engine procedures
20.7 Disconnecting a camshaft cover
breather hose -
2.0 litre engine20.11 Disconnecting the crankcase
breather tube stub hose -
1.6 litre engine
20.23 Cylinder head bolt loosening
sequence - SOHC engines20.19B Unbolting the crankcase breather
tube bracket from the cylinder head -
2.0 litre model20.19A Disconnecting the crankcase
breather tube stub hose -
2.0 litre engine
20.10 Unbolting the fuel injection wiring
harness earth leads from the camshaft
housing - 2.0 litre engine