1988 OPEL CALIBRA radiator cap

1General information and
precautions
The electrical system is of 12-volt negative
earth type. Power for the lights and all
electrical accessories is supplied by a
lead/acid type battery, which is charged by
the alternator.
This Chapter covers repair and service
procedures for the various electrical
components not associated with engine.
Information on the battery, alternator and
starter motor can be found in Chapter 5.
It should be noted that, before working on
any component in the electrical system, the
battery negative terminal should first be
disconnected, to prevent the possibility of
electrical short-circuits and/or fires.
Whenever the occasion arises, carefully
check the routing of the wiring harness,
ensuring that it is correctly secured by the
clips or ties provided so that it cannot chafe
against other components. Carefully check
points such as the clutch cable bracket,
clutch housing and harness support bracket,
the inlet manifold, the horn mounting bracket,
the starter motor terminals, and the rear
bumper and number plate lamp.
If evidence is found of the harness having
chafed against other components, repair the
damage and ensure that the harness is
secured or protected so that the problem
cannot occur again.
2Electrical fault-finding -
general information
Note:Refer to the precautions given in “Safety
first!” (at the beginning of this manual) and to
Section 1 of this Chapter before starting work.
The following tests relate to testing of the main
electrical circuits, and should not be used to
test delicate electronic circuits (such as anti-
lock braking systems), particularly where an
electronic control module is used.
A typical electrical circuit consists of an
electrical component, any switches, relays,
motors, fuses, fusible links or circuit breakers
related to that component, and the wiring and
connectors that link the component to boththe battery and the chassis. To help to
pinpoint a problem in an electrical circuit,
wiring diagrams are included at the end of this
Chapter.
Before attempting to diagnose an electrical
fault, first study the appropriate wiring
diagram, to obtain a complete understanding
of the components included in the particular
circuit concerned. The possible sources of a
fault can be narrowed down by noting
whether other components related to the
circuit are operating properly. If several
components or circuits fail at one time, the
problem is likely to be related to a shared fuse
or earth connection.
Electrical problems usually stem from
simple causes, such as loose or corroded
connections, a faulty earth connection, a
blown fuse, a melted fusible link, or a faulty
relay (refer to Section 3 for details of testing
relays). Visually inspect the condition of all
fuses, wires and connections in a problem
circuit before testing the components. Use
the wiring diagrams to determine which
terminal connections will need to be checked,
to pinpoint the trouble-spot.
The basic tools required for electrical fault-
finding include the following:
a)a circuit tester or voltmeter (a 12-volt bulb
with a set of test leads can also be used
for certain tests).
b)a self-powered test light (sometimes
known as a continuity tester).
c)an ohmmeter (to measure resistance).
d)a battery.
e)a set of test leads.
f)a jumper wire, preferably with a circuit
breaker or fuse incorporated, which can
be used to bypass suspect wires or
electrical components.
Before attempting to locate a problem with
test instruments, use the wiring diagram to
determine where to make the connections.
To find the source of an intermittent wiring
fault (usually due to a poor or dirty
connection, or damaged wiring insulation), a
“wiggle” test can be performed on the wiring.
This involves wiggling the wiring by hand, to
see if the fault occurs as the wiring is moved.
It should be possible to narrow down the
source of the fault to a particular section of
wiring. This method of testing can be used in
conjunction with any of the tests described in
the following sub-Sections.
Apart from problems due to poor
connections, two basic types of fault can
occur in an electrical circuit - open-circuit, or
short-circuit.
Open-circuit faults are caused by a break
somewhere in the circuit, which prevents
current from flowing. An open-circuit fault will
prevent a component from working, but will
not cause the relevant circuit fuse to blow.
Short-circuit faults are caused by a “short”
somewhere in the circuit, which allows the
current flowing in the circuit to “escape” along
an alternative route, usually to earth. Short-
circuit faults are normally caused by abreakdown in wiring insulation, which allows a
feed wire to touch either another wire, or an
earthed component such as the bodyshell. A
short-circuit fault will normally cause the
relevant circuit fuse to blow.
Finding an open-circuit
To check for an open-circuit, connect one
lead of a circuit tester or voltmeter to either
the negative battery terminal or a known good
earth.
Connect the other lead to a connector in
the circuit being tested, preferably nearest to
the battery or fuse.
Switch on the circuit, remembering that
some circuits are live only when the ignition
switch is moved to a particular position.
If voltage is present (indicated either by the
tester bulb lighting or a voltmeter reading, as
applicable), this means that the section of the
circuit between the relevant connector and
the battery is problem-free.
Continue to check the remainder of the
circuit in the same fashion.
When a point is reached at which no
voltage is present, the problem must lie
between that point and the previous test point
with voltage. Most problems can be traced to
a broken, corroded or loose connection.
Finding a short-circuit
To check for a short-circuit, first disconnect
the load(s) from the circuit (loads are the
components that draw current from a circuit,
such as bulbs, motors, heating elements, etc.).
Remove the relevant fuse from the circuit,
and connect a circuit tester or voltmeter to the
fuse connections.
Switch on the circuit, remembering that
some circuits are live only when the ignition
switch is moved to a particular position.
If voltage is present (indicated either by the
tester bulb lighting or a voltmeter reading, as
applicable), this means that there is a short-
circuit.
If no voltage is present, but the fuse still
blows with the load(s) connected, this indicates
an internal fault in the load(s).
Finding an earth fault
The battery negative terminal is connected
to “earth” (the metal of the
engine/transmission and the car body), and
most systems are wired so that they only
receive a positive feed. The current returning
through the metal of the car body. This means
that the component mounting and the body
form part of that circuit. Loose or corroded
mountings can therefore cause a range of
electrical faults, ranging from total failure of a
circuit, to a puzzling partial fault. In particular,
lights may shine dimly (especially when
another circuit sharing the same earth point is
in operation). Motors (e.g. wiper motors or the
radiator cooling fan motor) may run slowly,
and the operation of one circuit may have an
affect on another. Note that on many vehicles,
earth straps are used between certain
components, such as the engine/transmission
and the body, usually where there is no metal-
12•2Body electrical systems
Warning: Before carrying out
any work on the electrical
system, read through the
precautions given in “Safety
first!” at the beginning of this manual, and
in Chapter 5.
Caution:If the radio/cassette player fitted
to the vehicle is one with an anti-theft
security code, as the standard unit is, refer
to “Radio/cassette player anti-theft system
- precaution”in the Reference Section of
this manual before disconnecting the
battery.

1•4Maintenance schedule
Every 250 miles (400 km) or weekly
MRefer to “Weekly checks”
Basic service, every 9000 miles
(15 000 km) or 12 months -
whichever comes sooner
Along with the items in “Weekly checks”, carry out the
following:
MRenew the engine oil and oil filter (Section 3).
MCheck all hoses and other components for fluid
leaks (Section 4).
MCheck the steering and suspension components
(Section 5).
MCheck the condition of the driveshaft rubber
gaiters (Section 6).
MCheck the automatic transmission fluid level (if
applicable), (Section 7).
MCheck the radiator for blockage (e.g. dead insects)
and clean as necessary (Section 8).
MCheck and adjust the idle speed and mixture (if
applicable), (Section 9).
MCheck the throttle linkage and lubricate if
necessary (Section 10).
MCheck the exhaust system for corrosion, leaks and
security (Section 11).
MCheck all wiring for condition and security
(Section 12).
MCheck and adjust the ignition timing (if applicable),
(Section 13).
MRenew the brake fluid (Section 14).
MCheck the brake pad friction material for wear
(Section 15).
MCheck the handbrake linkage (Section 16).
MCheck the power steering fluid level (if applicable),
(Section 17).
MCheck the power steering pump drivebelt (if
applicable), (Section 18).
MCheck the rear suspension level control system
height, if fitted (Section 19).
MCheck the bodywork (Section 20).
MLubricate all locks and hinges (Section 21).
MCheck the alternator V-belt (Section 22).
MCheck the headlamp alignment (Section 23).
MReplace battery in the door-lock key (if applicable),
(Section 24).
MCarry out a road test (Section 25).
Note: Vauxhall specify that an Exhaust Emissions Test should be
carried out at least annually. However, this requires special
equipment, and is performed as part of the MOT test (refer to the
end of the manual).
Full service, every 18 000 miles
(30 000 km) or 24 months -
whichever comes sooner
Along with the ‘basic service’, carry out the following:
MRenew the coolant (Section 26).
MRenew the air cleaner element (Section 27).
MCheck the operation of the air cleaner air inlet
temperature control (carburettor models only),
(Section 28).
MRenew the fuel filter (Section 29).
MRenew the spark plugs (SOHC only), (Section 30) *.
MInspect and clean the distributor cap and HT leads
(Section 31).
MCheck the clutch cable adjustment (Section 32).
MCheck the manual transmission oil level (Section 33).
MCheck the automatic transmission (Section 34).
MCheck the brake drum shoe for wear (Section 35).
Major service, every 36 000 miles
(60 000 km) or 48 months -
whichever comes sooner
Along with the ‘full service’, carry out the following:
MRenew timing belt (Section 36).
MRenew the spark plugs (DOHC models only),
(Section 37).
MRenew automatic transmission fluid (Section 38) *.
* Note: If a vehicle is used for heavy-duty work (e.g. taxi work,
caravan/trailer towing, mostly short-distance, stop-start city driving)
the fluid must be changed every 36 months or 27 000 miles (45 000
km), whichever occurs first.

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

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

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.

level in the expansion tank, and top-up if
necessary. Note that the system must be cold
before an accurate level is indicated in the
expansion tank. If the expansion tank cap is
removed while the engine is still warm, cover
the 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.
9On DOHC models, refit the engine
undershield on completion.
5Coolant mixture -general
1It is important to use an antifreeze mixture
in the cooling system all year round, to
prevent corrosion of the alloy engine
components. The coolant mixture should be
made up from clean, preferably soft, tap
water, and a good quality antifreeze
containing corrosion inhibitor. Ensure that the
antifreeze is ethylene glycol based, as the
cheaper methanol based types evaporate
over a period of time.
2The proportions of water and antifreeze
used will depend on the degree of protection
required. A coolant mixture containing 25%
antifreeze should be regarded as the
minimum strength required to maintain good
anti-corrosion properties. Details of the
degree of protection provided against freezing
will be supplied with the antifreeze by the
manufacturers. For absolute protection, use a
50% antifreeze mixture.
3The coolant mixture should be renewed
every two years, as the corrosion inhibitors
will deteriorate with time.
4Before filling the system with fresh coolant,
drain and flush the system, as described in
Sections 2 and 3, and check that all hoses are
secure and that the clips are tight. Antifreeze
has a searching action, and will leak morerapidly than plain water.
5Refill the system as described in Section 4.
All future topping-up should be carried out
using a coolant mixture of the same
proportions as that used to initially fill the
system.
6Do not use antifreeze in the windscreen
wash system, as it will attack the vehicle
paintwork. Note that antifreeze is poisonous,
and must be handled with due care.
6Radiator (manual
transmission) -removal and
refitting
3
Removal
1The radiator can be removed complete with
the coolant fan and shroud if there is no need
to disturb the fan. If desired, the fan and its
shroud can be removed from the radiator,
with reference to Section 12.
2Drain the cooling system, as described in
Section 2.
3Disconnect the radiator top hose and the
expansion tank at the radiator.
4Disconnect the battery negative lead, then
disconnect the wiring from the cooling fan
switch, located at the bottom right-hand side
of the radiator.5Disconnect the cooling fan wiring
connector, noting its location for use when
refitting.
6Compress and remove the two radiator
securing clips, located at the top corners of
the radiator (see illustration).
7Pull the top of the radiator back towards the
engine to free it from the top mountings, then
lift the radiator to disengage the lower
securing lugs. Move the radiator clear of the
vehicle, taking care not to damage the cooling
fins (see illustrations).
Refitting
8The radiator can be inspected and cleaned
as described in Section 8.
9Refitting is a reversal of removal, bearing in
mind the following points.
10Ensure that the radiator rubber mountings
are in good condition and renew if necessary,
and ensure that the lower securing lugs
engage correctly as the radiator is refitted.
11Refill the cooling system, (Section 4).
7Radiator (automatic
transmission) -removal and
refitting
3
Removal
1On models with automatic transmission,
the radiator left-hand side tank incorporates a
heat exchanger to cool the transmission fluid.
It is connected to the transmission by a pair of
flexible hoses, with a metal pipe at each end.
2When removing the radiator, either clamp
the transmission fluid cooler flexible hoses, or
slacken their clamps, work them off their
unions and swiftly plug or cap each hose end
and union to minimise the loss of fluid and to
prevent the entry of dirt.
Refitting
3On refitting, reverse the removal procedure
and do not forget to check the transmission
fluid level, topping-up as necessary to replace
the lost fluid, as described in Chapter 7B.
Cooling, heating and ventilation systems 3•3
6.7B Withdrawing the radiator -
2.0 litre SOHC model6.7A Radiator freed from top right-hand mounting -
1.6 litre model
6.6 Compressing a radiator securing clip -
2.0 litre SOHC model
3

4Position a container beneath the tank, then
disconnect the bottom hose and allow the
contents of the tank to drain into the
container. Suspend the bottom hose as high
as possible above the engine to prevent
coolant loss.
Refitting
5Refitting is a reversal of removal, but on
completion check and if necessary top-up the
coolant level, as described in Section 4. The
coolant drained from the expansion tank
during removal can be re-used, provided it
has not been contaminated.
Coolant level sensor
6The coolant level sensor, where fitted, is an
integral part of the expansion tank cap. If the
level sensor is faulty, the complete cap
assembly must be renewed.
14Temperature gauge sender -
removal and refitting
2
Removal
1The sender is screwed into the inlet
manifold on 1.4 and 1.6 litre models (except
C16 NZ2), and into the thermostat housing
on C16 NZ2, 1.8 and 2.0 litre models (see
illustrations).
2Partially drain the cooling system, as
described in Section 2, to minimise coolant
spillage.
3Disconnect the battery negative lead.4Disconnect the wiring from the switch, then
unscrew the switch from its location.
Refitting
5Refitting is a reversal of removal,
remembering the following points.
6Coat the sender threads with sealant before
fitting.
7Top-up the cooling system, as described in
Section 4.
8On completion, start the engine and check
the operation of the temperature gauge. Also
check for coolant leaks.
15Cooling fan switch -removal
and refitting
3
Note: A new sealing ring should be used
when refitting the switch
Removal
1The cooling fan switch is located at the
bottom right-hand corner of the radiator (see
illustration).
2If a faulty switch is suspected, the circuit to
the fan motor can be tested by temporarily
bridging the terminals in the switch wiring
plug, and switching on the ignition. If the
cooling fan now operates, the switch is faulty
and should be renewed. To remove the
switch, continue as follows.
3Disconnect the battery negative lead, then
disconnect the switch wiring plug if not
already done.4Drain the cooling system, as described in
Section 2.
5Unscrew the switch from the radiator and
recover the sealing ring.
Refitting
6Refitting is a reversal of removal, but use a
new sealing ring, and refill the cooling system
as described in Section 4.
7On completion, start the engine and run it
until it reaches normal operating temperature,
then continue to run the engine and check
that the cooling fan cuts in and functions
correctly.
16Heater control panel -
removal and refitting
3
Removal
1Disconnect the battery negative lead.
2Remove the passenger side footwell trim,
the steering column shrouds, and the
instrument panel lower and upper trim panels,
as described in Chapter 11.
3Remove the clock or trip computer, as
applicable, from the facia, referring to Chapter
12 if necessary.
4Remove the two heater control panel
securing screws from the clock/trip computer
aperture, and the remaining securing screw
from the right-hand end of the panel (exposed
by removing the instrument panel lower trim
panel), (see illustrations).
3•6Cooling, heating and ventilation systems
14.1A Disconnecting the wiring from the
temperature gauge sender - 1.6 litre model14.1C Temperature gauge sender location
(arrowed) - 2.0 litre DOHC model
16.4B . . . and the remaining screw from
the right-hand end of the panel16.4A Remove the two heater control
panel securing screws from the clock/trip
computer aperture . . .15.1 Cooling fan switch location -
2.0 litre SOHC model viewed from below
14.1B Temperature gauge sender location
(arrowed) - 2.0 litre SOHC model