1•6Maintenance - component location
Underbonnet view of a 1989 2.0 SRi model (20 SEH engine)
1 VIN plate
2 Air cleaner casing
3 Airflow meter
4 Suspension strut top
5 Coolant expansion tank
6 Brake fluid reservoir
7 Throttle body
8 Relay box
9 Octane rating plug
10 Washer fluid reservoir
11 Battery
12 Power steering fluid reservoir
13 Power steering fluid hoses
14 Distributor cap
15 Engine oil level dipstick
16 Idle speed adjuster
17 Fuel pressure regulator
18 Oil filler cap
19 Thermostat housing
Underbonnet view of a 1990 GSi 2000 model (20 XEJ engine)
1 VIN plate
2 Air cleaner casing
3 Suspension strut top
4 Coolant expansion tank
5 Brake fluid reservoir
6 Air mass meter
7 Fuel pressure regulator
8 Relay box
9 Anti-theft alarm horn
10 ABS hydraulic modulator
11 Washer fluid reservoir
12 Power steering fluid reservoir
13 Battery
14 Distributor
15 Engine oil level dipstick
16 Oil filler cap
Maintenance - component location 1•7
1
Front underbody view of a 1989 1.6 L model (16 SV engine)
1 Brake caliper
2 Subframe
3 Oil filter
4 Clutch cover plate
5 Suspension lower arm
6 Differential cover plate
7 Engine oil drain plug
8 Driveshaft gaiter
9 Exhaust pipe
10 Anti-roll bar securing nut
Rear underbody view of a 1989 2.0 SRi model (semi-independent rear suspension)
1 Torsion beam
2 Trailing arm
3 Anti-roll bar
4 Shock absorber
5 Coil spring
6 Exhaust expansion box
7 Fuel flow damper
8 Fuel filter
9 Fuel tank securing strap
10 Handbrake cable
1Introduction
This Chapter is designed to help the home
mechanic maintain his/her vehicle for safety,
economy, long life and peak performance.
The Chapter contains a master maintenance
schedule, followed by Sections dealing specifically
with each task in the schedule. Visual checks,
adjustments, component renewal and other helpful
items are included. Refer to the accompanying
illustrations of the engine compartment and the
underside of the vehicle for the locations of the
various components.
Servicing your vehicle according to the
mileage/time maintenance schedule and the
following Sections will provide a planned
maintenance programme, which should result in a
long and reliable service life. This is a comprehensiveplan, so maintaining some items but not others at
the specified service intervals, will not produce the
same results.
As you service your vehicle, you will
discover that many of the procedures can -
and should - be grouped together, because of
the particular procedure being performed, or
because of the proximity of two otherwise-
unrelated components to one another. For
example, if the vehicle is raised for any
reason, the exhaust can be inspected at the
same time as the suspension and steering
components.
The first step in this maintenance
programme is to prepare yourself before the
actual work begins. Read through all the
Sections relevant to the work to be carried
out, then make a list and gather all the parts
and tools required. If a problem is found, seek
advice from a parts specialist, or a dealer
service department.
2Intensive maintenance
If, from the time the vehicle is new, routine
maintenance schedule is followed closely,
frequent checks made of fluid levels and high-
wear items, as recommended, the engine will
be kept in relatively good running condition.
The need for additional work will be minimised
It is possible that there will be times when
the engine is running poorly due to the lack of
regular maintenance. This is even more likely
if a used vehicle, which has not received
regular and frequent maintenance checks, is
purchased. In such cases, additional work
may need to be carried out, outside of the
regular maintenance intervals.
If engine wear is suspected, a compression
1•8Maintenance - component location
Rear underbody view of a 1990 GSi 2000 model (fully independent rear suspension)
1 Fuel tank securing strap
2 Shock absorber
3 ABS wheel sensor
4 Semi-trailing arm
5 Suspension crossmember
mounting bracing bracket
6 Handbrake cable
7 Suspension crossmember
8 Exhaust expansion box
9 Fuel pump
Maintenance procedures
test (refer to Chapter 2A) will provide valuable
information regarding the overall performance
of the main internal components. Such a test
can be used as a basis to decide on the
extent of the work to be carried out. If, for
example, a compression test indicates serious
internal engine wear, conventional
maintenance as described in this Chapter will
not greatly improve the performance of the
engine. It may also prove a waste of time and
money, unless extensive overhaul work is
carried out first.
The following series of operations are those
most often required to improve the
performance of a generally poor-running
engine:Primary operations
a)Clean, inspect and test the battery (See
“Weekly Checks”)
b)Check all the engine related fluids (See
“Weekly Checks”)
c)Check the condition and tension of the
auxiliary drivebelt (Sections 18 and 22, as
appropriate).
d)Renew the spark plugs (Sections 30 and
37, as appropriate).
e)Inspect the distributor cap, rotor arm and
HT leads, as applicable (Section 31).
f)Check the condition of the air filter, and
renew if necessary (Section 27).
g)Check the fuel filter (Section 29).
h)Check the condition of all hoses, and
check for fluid leaks (Section 4).i)Check the idle speed and mixture
settings, as applicable (Section 9).
5If the above operations do not prove fully
effective, carry out the following secondary
operations:
Secondary operations
All items listed under “Primary operations”,
plus the following:
a)Check the charging system (Chapter 5).
b)Check the ignition system (Chapter 5).
c)Check the fuel system (Chapters 4A and
4B).
d)Renew the distributor cap and rotor arm
(Section 31).
e)Renew the ignition HT leads (Section 31).
3Engine oil and filter - renewal
2
1Ideally, the oil should be drained with the
engine hot, just after the vehicle has been
driven.
2On DOHC models, remove the engine
undershield to expose the sump drain plug
and the oil filter.
3Place a container beneath the oil drain plug
at the rear of the sump.
4Remove the oil filler cap from the camshaft
cover, then using a socket or spanner,
unscrew the oil drain plug, and allow the oil to
drain (see illustration). Take care to avoid
scalding if the oil is hot.
5Allow ten to fifteen minutes for the oil to
drain completely, then move the container
and position it under the oil filter.6On 1.8 and 2.0 litre models, improved
access to the oil filter can be gained by
jacking up the front of the vehicle and
removing the right-hand roadwheel (see
illustration). Ensure that the handbrake is
applied, and that the vehicle is securely
supported on axle stands (see “Jacking and
Vehicle Support”). Note that further oil may
drain from the sump as the vehicle is raised.
7Using a strap wrench or a filter removal tool
if necessary, slacken the filter and unscrew it
from the mounting. Alternatively, if the filter is
very tight, a screwdriver can be driven
through the filter casing and used as a lever.
Discard the filter.
8Wipe the mating face on the filter mounting
with a lint-free rag, then smear the sealing ring
of the new filter with clean engine oil of the
specified grade.
9Screw the new filter into position and
tighten it by hand only, do not use any tools.
10Where applicable, refit the roadwheel and
lower the vehicle to the ground. Fully tighten
the roadwheel bolts with the vehicle resting on
its wheels.
11Examine the condition of the oil drain plug
sealing ring and renew if necessary, then refit
the drain plug and tighten it to the specified
torque. 12Refill the engine through the filler on the
camshaft cover, using the specified grade and
quantity of oil. Fill until the level reaches the
“MAX” mark on the dipstick, allowing time for
the oil to drain through the engine to the
sump.
13Refit the oil filler cap, then start the engine
and check for leaks. Note that the oil pressure
warning lamp may stay illuminated for a few
seconds when the engine is started as the oil
filter fills with oil.
14Stop the engine and recheck the oil level,
topping-up if necessary.
15On DOHC models, refit the engine
undershield.
16Dispose of the old engine oil safely; do not
pour it down a drain.
4Hose and fluid leak check
1
1Visually inspect the engine joint faces,
gaskets and seals for any signs of water or oil
leaks. Pay particular attention to the areas
around the camshaft cover, cylinder head, oil
filter and sump joint faces. Remember that,
over a period of time, some very slight
seepage from these areas is to be expected -
what you are really looking for is any
indication of a serious leak. Should a leak be
found, renew the offending gasket or oil seal
by referring to the appropriate Chapters in this
manual.
Every 9000 miles or 12 months 1•9
3.6 Oil filter viewed through right-hand
wheel arch - SOHC model3.4 Sump drain plug location -
2.0 litre DOHC model
(engine undershield removed)
1
Basic service, every 9000 miles (15 000 km) or 12 months
As the drain plug releases
from the threads, move it
away quickly so the stream
of oil, running out of the
sump, goes into the container not up
your sleeve (see illustration).
Note: It is
antisocial and
illegal to dump oil
down the drain.
To find the
location of your
local oil recycling
bank, call this
number free.
2Also check the security and condition of all
the engine related pipes and hoses. Ensure
that all cable-ties or securing clips are in
place, and in good condition. Clips that are
broken or missing can lead to chafing of the
hoses, pipes or wiring, which could cause
more serious problems in the future.
3Carefully check the radiator hoses and
heater hoses along their entire length. Renew
any hose that is cracked, swollen or
deteriorated. Cracks will show up better if the
hose is squeezed. Pay close attention to the
hose clips that secure the hoses to the
cooling system components. Hose clips can
pinch and puncture hoses, resulting in cooling
system leaks. It is always beneficial to renew
hose clips whenever possible.
4Inspect all the cooling system components
(hoses, joint faces, etc.) for leaks.
5Where any problems are found on system
components, renew the component or gasket
with reference to Chapter 3.
6Where applicable, inspect the automatic
transmission fluid cooler hoses for leaks or
deterioration.
7With the vehicle raised, inspect the petrol
tank and filler neck for punctures, cracks and
other damage. The connection between the
filler neck and tank is especially critical.
Sometimes a rubber filler neck or connecting
hose will leak due to loose retaining clamps or
deteriorated rubber.
8Carefully check all rubber hoses and metal
fuel lines leading away from the petrol tank.
Check for loose connections, deteriorated
hoses, crimped lines, and other damage. Pay
particular attention to the vent pipes and
hoses, which often loop up around the filler
neck and can become blocked or crimped.
Follow the lines to the front of the vehicle,
carefully inspecting them all the way. Renew
damaged sections as necessary.
9From within the engine compartment,
check the security of all fuel hose attachments
and pipe unions, and inspect the fuel hoses
and vacuum hoses for kinks, chafing and
deterioration.
10Where applicable, check the condition of
the power steering fluid hoses and pipes.5Steering and suspension
check
2
Front suspension and steering
check
1Raise the front of the car, and support on
axle stands (“Jacking and Vehicle Support”).
2Visually inspect the balljoint dust covers
and the steering rack-and-pinion gaiters for
splits, chafing or deterioration. Any wear of
these components will cause loss of lubricant,
together with dirt and water entry, resulting in
rapid wear of the balljoints or steering gear.
3On vehicles with power steering, check the
fluid hoses for chafing or deterioration, and
the pipe and hose unions for fluid leaks. Also
check for signs of fluid leakage under
pressure from the steering gear rubber
gaiters, which would indicate failed fluid seals
within the steering gear.
4Grasp the roadwheel at the 12 o’clock and
6 o’clock positions, and try to rock it (see
illustration). Very slight free play may be felt,
but if the movement is appreciable, further
investigation is necessary to determine the
source. Continue rocking the wheel while an
assistant depresses the footbrake. If the
movement is now eliminated or significantly
reduced, it is likely that the hub bearings are
at fault. If the free play is still evident with the
footbrake depressed, then there is wear in the
suspension joints or mountings.
5Now grasp the wheel at the 9 o’clock and 3
o’clock positions, and try to rock it as before.
Any movement felt now may again be caused
by wear in the hub bearings or the steering
track-rod balljoints. If the inner or outer balljoint
is worn, the visual movement will be obvious.
6Using a large screwdriver or flat bar, check
for wear in the suspension mounting bushes
by levering between the relevant suspension
component and its attachment point. Some
movement is to be expected as the mountings
are made of rubber, but excessive wear
should be obvious. Also check the condition
of any visible rubber bushes, looking for splits,
cracks or contamination of the rubber.
7Inspect the front suspension lower arms for
distortion or damage (Chapter 10, Section 5).
8With the car standing on its wheels, have an
assistant turn the steering wheel back and
forth about an eighth of a turn each way.
There should be very little, if any, lost
movement between the steering wheel and
roadwheels. If this is not the case, closely
observe the joints and mountings previously
described, but in addition, check the steering
column universal joints for wear, and the rack-
and-pinion steering gear itself.
Suspension strut/shock
absorber check
Note:Suspension struts/shock absorbers
should always be renewed in pairs on the
same axle.9Check for any signs of fluid leakage around
the suspension strut/shock absorber body, or
from the rubber gaiter around the piston rod.
Should any fluid be noticed, the suspension
strut/shock absorber is defective internally,
and should be renewed.
10The efficiency of the suspension
strut/shock absorber may be checked by
bouncing the vehicle at each corner. The body
will return to its normal position and stop after
being depressed. If it rises and returns on a
rebound, the suspension strut/shock
absorber is probably suspect. Examine also
the suspension strut/shock absorber upper
and lower mountings for any signs of wear.
6Driveshaft gaiter check
2
With the vehicle raised and securely
supported on stands, turn the steering onto
full lock, then slowly rotate the roadwheel.
Inspect the condition of the outer constant
velocity (CV) joint rubber gaiters, squeezing
the gaiters to open out the folds (see
illustration). Check for signs of cracking,
splits or deterioration of the rubber, which
may allow the grease to escape, and lead to
water and grit entry into the joint. Also check
the security and condition of the retaining
clips. Repeat these checks on the inner CV
joints. If any damage or deterioration is found,
the gaiters should be renewed as described in
Chapter 8.
1•10Every 9000 miles or 12 months
6.1 Check the condition of the driveshaft
gaiters (A) and clips (B)
5.4 Check for wear in the hub bearings by
grasping the wheel and trying to rock it
A leak in the cooling system will usually
show up as white or rust coloured
deposits on the area adjoining the leak
28Air inlet temperature control
check (carburettor models
only)
2
Refer to Chapter 4A for details.
29Fuel filter renewal
3
Fuel filters are fitted in various locations
throughout the range. Some may be ‘in-line’ in
the fuel tank itself, or fitted into the
carburettor.
Refer to Chapters 4A or 4B, as appropriate.
30Spark plug renewal (SOHC)
2
1The correct functioning of the spark plugs is
vital for the correct running and efficiency of
the engine. It is essential that the plugs fitted
are appropriate for the engine. Refer to the
specifications in Chapter 5. If this type is used
and the engine is in good condition, the spark
plugs should not need attention between
scheduled service replacement intervals.
Spark plug cleaning is rarely necessary and
should not be attempted unless specialised
equipment is available, as damage can easily
be caused to the firing ends.
2Identify each HT lead for position so that the
leads can be refitted to their correct cylinders.
Then disconnect the leads from the plugs by
pulling on the connectors, not the leads.
3Clean the area around each spark plug
using a small paintbrush, then using a plugspanner (preferably with a rubber insert),
unscrew and remove the plugs (see
illustration). Cover the spark plug holes with
a clean rag to prevent the ingress of any
foreign matter.
4The condition of the spark plugs will tell
much about the overall condition of the
engine.
5If the insulator nose of the spark plug is
clean and white, with no deposits, this is a
sign of a weak mixture, or too hot a plug (a hot
plug transfers heat away from the electrode
slowly -a cold plug transfers heat away
quickly).
6If the tip and insulator nose is covered with
hard black-looking deposits, then this is
indicative that the mixture is too rich. Should
the plug be black and oily, then it is likely that
the engine is fairly worn, as well as the mixture
being too rich.
7If the insulator nose is covered with light tan
to greyish brown deposits, then the mixture is
correct, and it is likely that the engine is in
good condition.
8The spark plug gap is of considerable
importance, because if it is either too large or
too small, the size of the spark and its
efficiency will be seriously impaired. The spark
plug gap should be set to the figure given in
the Specifications, in Chapter 5.
9To set it, measure the gap with a feeler
blade and then bend open, or close, the outer
plug electrode until the correct gap is
achieved. The centre electrode should never
be bent, as this may crack the insulation and
cause plug failure, if nothing worse (see
illustrations).10Before fitting new spark plugs check that
their threaded connector sleeves are tight.
11Screw in the plugs by hand, then tighten
them to the specified torque. Do not exceed
the torque figure.
12Push the HT leads firmly onto the spark
plugs, ensuring that they are connected to
their correct cylinders.
31Distributor cap and HT lead
check
3
1Remove the distributor cap and HT leads,
and wipe them clean.
2Also wipe clean the coil connections.
Remove the rotor arm, then visually check the
distributor cap, rotor arm and HT leads for
hairline cracks, and signs of arcing.
1•14Every 18 000 miles or 24 months
30.9A Tools required for spark plug
removal, gap adjustment and refitting30.9C Measuring the spark plug gap with
feeler blade30.9B Measuring the spark plug gap with
wire gauge
30.3 Removing a spark plugWarning: Before carrying out
the following operation, refer to
the precautions given in “Safety
first!” at the beginning of this
manual, and follow them implicitly. Petrol
is a highly dangerous and volatile liquid,
and the precautions necessary when
handling it cannot be overstressed.
It is very often difficult to insert spark
plugs into their holes without cross-
threading them. To avoid this, fit a
short length of 8 mm (internal
diameter), rubber hose over the end of
the spark plug. The flexible hose acts
as a universal joint to help align the
plug correctly. Should the plug begin to
cross-thread, the hose will slip on the
spark plug, preventing damage to the
thread in the cylinder head.
Number the HT leads before
removal to ensure correct
refitting.
Torque wrench settings (continued)Nmlbf ft
Starter to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4533
Starter support to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Temperature regulator plug (M20) * . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Timing belt cover . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86
Timing belt drive gear to crankshaft: *
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250184
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by between 40°and 50°
Timing belt guide roller bracket to block . . . . . . . . . . . . . . . . . . . . . . . .2518
Timing belt guide roller to bracket . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Timing belt guide roller to cylinder block:
Engines up to 1993
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by 45°
Stage 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by 15°
1993-on engines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Transfer box bracket to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . .6044
Transmission to cylinder block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6044
1General
This part of Chapter 2 describes
procedures that are specific to the DOHC
engine. It should be read in conjunction with
Part A.
The lower engine is basically the same as
the 2.0 litre SOHC. However the pistons are
attached to the connecting rods by gudgeon
pins, which are fully floating, and are secured
by circlips.
Both camshafts on these engines are driven
from the crankshaft by one toothed
composite rubber belt. Each cylinder has four
valves (two inlet and two exhaust), operated
directly from the camshafts by hydraulic
self-adjusting valve lifters. One camshaft
operates the inlet valves, and the other
operates the exhaust valves.
DOHC models are fitted with a remotely
mounted oil cooler.
The distributor is driven directly from the
exhaust camshaft.
2Engine - removal and refitting
4
Removal
1Carry out procedure in Chapter 2A, noting
the following differences.
2With the car safely raised, remove the
engine undershield.
3The fuel hoses need to be disconnected
from the fuel rail.
4Disconnect coolant hoses from the cylinder
block and cylinder head. Also disconnect the
oil cooler pipe unions from the oil pump.
5Unbolt the right-hand driveshaft centre
bearing support bracket from the rear of the
cylinder block.
Refitting
6Refitting the engine is similar to theprocedure in Chapter 2A. The exceptions
being, replacement of the right-hand
driveshaft centre bearing support bracket at
the rear of the cylinder block and retightening
the securing bolts.
7Replace the undershield.
3Engine/transmission
mountings- renewal
3
The procedure for replacing the engine/
transmission is similar to SOHC models, see
Chapter 2A. However this engine is fitted with
an undershield that needs to be removed
before replacing the mounts. Do not forget to
replace the undershield before lowering the
car.
4Timing belt, sprockets and belt
tensioner and idler pulleys-
removal, refitting and adjustment
3
Note: The timing belt should be renewed on
refitting. A two-legged puller may be required
to remove the crankshaft sprocket
Removal
1Disconnect the battery negative lead.2Disconnect the air cleaner trunking from the
airflow meter, then remove the cover and the
air cleaner element from the air cleaner. If
desired, for improved access, the complete
air cleaner assembly can be removed, as
described in Chapter 4B.
3Remove the power steering pump drivebelt,
as described in Chapter 10.
4Remove the alternator drivebelt, as
described in Chapter 5.
5Remove the three securing screws, and
withdraw the outer timing belt cover. Recover
the rubber grommets from the screw holes in
the cover if they are loose.
6Turn the crankshaft using a Torx socket on
the crankshaft sprocket bolt, until the timing
marks on the camshaft sprockets are aligned
with the notches in the camshaft cover. The
notch in the crankshaft pulley should also be
aligned with the pointer on the rear timing belt
cover (see illustrations).
7Extract the six securing bolts using a
splined bit, and withdraw the crankshaft
pulley (see illustration). If necessary,
counterhold the crankshaft using a socket on
the crankshaft sprocket bolt. If the engine is in
the vehicle, the crankshaft can be prevented
from turning by having an assistant engage
first gear and depress the brake pedal.
Alternatively, the flywheel ring gear teeth can
be jammed using a large screwdriver or
similar tool. Before removing the pulley, check
that the timing marks are still aligned.
DOHC engine procedures 2B•3
4.6B . . .and notch in crankshaft pulley
aligned with pointer on rear timing belt
cover (circled)4.6A Camshaft sprocket TDC mark
aligned with notch in camshaft cover
2B
pitting. If evident, the cylinder head and all
bearing caps must be renewed as a matched
set, as there is no provision for refacing if the
bearing caps cannot be renewed individually.
8The camshaft(s) should show no marks or
scoring on the journal or cam lobe surfaces. if
evident, renew the camshaft(s).
9It is advisable to renew the camshaft front
oil seal(s) as a matter of course. Prise the old
seal(s) from the front of the camshaft(s) and
discard them.
Refitting
10Begin refitting by liberally coating the
contact faces of the hydraulic valve lifters and
the camshaft(s) with molybdenum disulphide
paste.
11Coat the mating faces of the front and
rear bearing caps with sealing compound and
refit the bearing caps in their original positions
as noted during removal.
12Tighten the camshaft bearing cap nuts to
the specified torque in half-turn stages, as
when loosening the nuts. Note that when
refitting the exhaust camshaft, the two smaller
rear bearing cap securing nuts should be
tightened after all the main camshaft bearing
cap nuts have been tightened. Note also that
the two smaller nuts should be tightened to a
lower torque wrench setting than the main
nuts.
13Turn the camshaft until the locating peg
for the camshaft sprocket is uppermost, then
lubricate the lips of a rear camshaft front oil
seal with a little grease, and fit the oil seal,
using a tube or socket of similar diameter with
a washer and the camshaft sprocket bolt.
Screw the camshaft sprocket bolt into the end
of the camshaft to draw the oil seal into
position on its shoulder.
14Repeat the procedure for the remaining
camshaft.
15Refit the distributor with reference to
Chapter 5. Fit a new timing belt and the
camshaft sprockets, then adjust the timing
belt as described in Section 4 or 5, as
applicable.
8Cylinder head -removal and
refitting (engine in vehicle)
4
Note: The engine must be cold when the
cylinder head is removed. Do not remove the
cylinder head from a hot engine. New cylinder
head bolts, a new cylinder head gasket and a
new timing belt must be used on refitting.
The torque settings (as shown in Chapter 2A)
are only applicable to latest specification head
bolts, available from Vauxhall. Earlier type or
alternative make, head bolts may require
different torques. Consult your supplier
Removal
1Disconnect the battery negative lead.
2Drain the cooling system, as described in
Chapter 3.3Remove the front section of the exhaust
system, as described in Chapter 4C.
4The cylinder head can be removed
complete with the inlet manifold, or the inlet
manifold can be detached from the cylinder
head before removal, with reference to
Chapter 4B. If no work is to be carried out on
the inlet manifold, it can be unbolted from the
cylinder head and supported to one side out
of the way, thus avoiding the need to
disconnect the relevant hoses, pipes and
wiring.
5If the cylinder head is to be removed
complete with the inlet manifold, disconnect
all relevant hoses, pipes and wiring from the
inlet manifold and associated components,
referring to Chapter 4B, and unbolt the
manifold support bracket from the manifold.
Loosen the alternator mountings with
reference to Chapter 5, then unbolt the upper
alternator mounting from the inlet manifold.
6If the inlet manifold is to be left in the engine
compartment, continue as follows, otherwise
go on to paragraph 17.
7Disconnect the wiring plug from the airflow
meter, and the breather hose from the air box
on the throttle body. Disconnect the air
cleaner trunking and remove the airflow
meter/air box assembly from the throttle
body. Refer to Chapter 4B if necessary.
8Disconnect the end of the throttle cable
from the throttle valve lever, then unbolt the
throttle cable support bracket and remove it
from the inlet manifold.
9Unscrew the two earth lead securing nuts
from the fuel rail (one at each end of the rail)
and disconnect the three earth leads.
10Disconnect the wiring plug from the
throttle position switch.
11Pull up on the wiring harness housing, and
disconnect the wiring plugs from the fuel
injectors by compressing the retaining clips.
Move the wiring harness housing to one side.
12Disconnect the two breather hoses from
the rear of the camshaft cover.
13Loosen the alternator mountings, with
reference to Chapter 5, then unbolt the upper
alternator mounting from the inlet manifold.
14Unbolt the manifold support bracket from
the manifold.15Make a final check to ensure that all
necessary hoses, pipes and wires have been
disconnected, then unscrew the securing nuts
and lift the inlet manifold from the cylinder
head. Ensure that the manifold is properly
supported, taking care not to strain any of the
hoses, pipes and wires, etc., which are still
connected.
16Recover the manifold gasket from the
cylinder head.
17Remove the timing belt, camshaft
sprockets, and timing belt tensioner and idler
pulleys, as described in Section 4.
18Unscrew the upper and middle studs for
the timing belt outer cover screws. Note that
the upper stud simply unscrews from the
cylinder head, but the middle stud is secured
by a bolt.
19Unscrew the two upper rear timing belt
cover securing bolts from the cylinder head.
20Remove the distributor cap and HT leads
with reference to Chapter 5.
21Disconnect the distributor wiring plug.
22Disconnect the coolant hose from the
left-hand end of the cylinder head.
23Unscrew the bolt securing the crankcase
breather tube bracket to the end of the
cylinder head.
24Disconnect the radiator top hose from the
thermostat housing, and disconnect the
wiring plugs from the temperature gauge
sender and the coolant temperature sensor
(both situated in the thermostat housing).
25Make a final check to ensure that all
relevant hoses, pipes and wires have been
disconnected.
26On X20 XEV models, remove the
camshaft, as described in Section 7.
27Using a Torx socket, and working in the
order shown (see illustrations), loosen all the
cylinder head bolts by a quarter of a turn, then
loosen all the bolts by half a turn, and finally
loosen and remove the bolts. Recover the
washers. Note that the loosening sequence
on X20 XEV differs to other DOHC engines.
28Lift the cylinder head from the cylinder
block. If necessary, tap the cylinder head
gently with a soft-faced mallet to free it from
the block, but do not lever at the mating
faces. Note that the cylinder head is located
on dowels.
DOHC engine procedures 2B•7
8.27B Cylinder head bolt loosening
sequence - (X 20 XEV engines)8.27A Cylinder head bolt loosening
sequence - (20 XEJ and C 20 XE engines)
2B