1988 OPEL CALIBRA length

18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH:
New belt, cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5
New belt, warm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.5
Used belt, cold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.5
Used belt, warm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.0
Valves and guidesInletExhaust
Overall length - production (mm):
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105.0105.0
16 SV, X 16 SZ and C16 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101.5101.5
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104.2104.2
18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . . . . . . . . . .104.2104.0
Overall length - service (mm):
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104.6104.6
16 SV, X 16 SZ and C16 NZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101.1101.1
C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103.8103.8
18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . . . . . . . . . .103.8103.6
Head diameter (mm):
14 NV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33.029.0
16 SV, X 16 SZ, C16 NZ and C16 NZ2 . . . . . . . . . . . . . . . . . . . . . . . .38.031.0
18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . . . . . . . . . . . .41.836.5
Stem diameter (mm), (all engines):
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6.998 to 7.0126.978 to 6.992
0.075 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.073 to 7.0877.053 to 7.067
0.150 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.148 to 7.1627.128 to 7.142
0.250 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.248 to 7.2627.228 to 7.242
Valve guide bore (mm), (all engines):
Standard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.030 to 7.050
0.075 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.105 to 7.125
0.150 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.180 to 7.200
0.250 mm oversize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.280 to 7.300
Valve clearance in guide (mm), (all engines):
Inlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.018 to 0.052
Exhaust . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.038 to 0.072
Valve seat angle:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44º
Valve clearances:
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Automatic adjustment by hydraulic lifters
Flywheel
Maximum permissible lateral run-out of starter ring gear (all models) . .0.5 mm
Refinishing limit -maximum depth of material that may be removed
from clutch friction surface (all models) . . . . . . . . . . . . . . . . . . . . . . .0.3 mm
Lubrication system
Lubricant type/specification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Lubricants and fluids in “Weekly checks”
Lubricant capacity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .See Chapter 1 Specifications
Oil pump clearances:
Inner-to-outer gear teeth clearance (backlash) (all models) . . . . . . . .0.0 to 0.2 mm
Gear-to-housing clearance (endfloat):
14 NV, 16 SV, C16 NZ and X 16 SZ . . . . . . . . . . . . . . . . . . . . . . . .0.08 to 0.15 mm
C16 NZ2, 18 SV, C18 NZ, 20 NE, C20 NE and 20 SEH . . . . . . . . .0.03 to 0.10 mm
Oil pressure at idle (engine warm) (all models) . . . . . . . . . . . . . . . . . . . .1.5 bar (21.8 lbf/in2
)
Torque wrench settingsNmlbf ft
Note:Use new bolts where asterisked (*). The torque settings stated for the cylinder head are only applicable to latest specification bolts, available
from Vauxhall. Earlier type or alternative make, head bolts may require different torques. Consult your supplier.
Air inlet pre-heat to exhaust manifold . . . . . . . . . . . . . . . . . . . . . . . . . .86
Alternator and inlet manifold to brackets:
1.4 and 1.6 litre, (except C16 NZ2) . . . . . . . . . . . . . . . . . . . . . . . . . . .2015
C16 NZ2, 1.8 and 2.0 litre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1813
Alternator to bracket (M8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3022
Alternator to bracket (M10) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4030
Alternator to shackle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Big-end bearing cap: *
1.4 and 1.6 litre, (except C16 NZ2)
Stage 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2518
Stage 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Angle tighten by 30º
SOHC engine procedures 2A•5
2A

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.

7Repeat the procedure for the remaining
valves, keeping all components in strict order,
so that they can be refitted in their original
positions (see illustration).
8The cylinder head and valves can be
inspected for wear and damage as described
in Section 23.
Reassembly
9With all components cleaned, begin
reassembly as follows.
10Starting at one end of the cylinder head,
fit the valve components as follows.
11Insert the appropriate valve into its guide,
ensuring that the valve stem is well lubricated
with clean engine oil (see illustration). Note
that if the original components are being
refitted, all components must be refitted in
their original positions.
12Fit the spring seat (see illustration).13New valve stem oil seals should be
supplied with a fitting sleeve, which fits over
the collet groove in the valve stem, to prevent
damage to the oil seal as it is slid down the
valve stem (see illustration). If no sleeve is
supplied, wind a short length of tape round the
top of the valve stem to cover the collet groove.
14Push the valve stem oil seal down the
valve stem using a tube until the seal is fully
engaged with the spring seat (see
illustrations). Remove the fitting sleeve or
tape, as applicable, from the valve stem.
15Fit the valve spring and the spring cap
(see illustrations).
16Fit the spring compressor tool, and
compress the valve spring until the spring cap
passes beyond the collet groove in the valve
stem.
17Apply a little grease to the collet groove,
then fit the split collets into the groove, withthe narrow ends nearest the spring (see
illustration). The grease should hold them in
the groove.
18Slowly release the compressor tool,
ensuring that the collets are not dislodged
from the groove. When the compressor is fully
released, give the top of the valve assembly a
sharp tap with a soft-faced mallet to settle the
components.
19Repeat the procedure for the remaining
valves, ensuring that all components are
refitted in their original positions, where
applicable.
20Where applicable, refit the manifolds as
described in Chapter 4A, 4B or 4C, and/or the
thermostat and thermostat housing as
described in Chapter 3. Refit the spark plugs
if desired.
21Refit the cylinder head as described in
Section 21.
SOHC engine procedures 2A•23
22.12 Fit the valve seat (exhaust valve
shown)
22.17 Retain the split collets with a little
grease22.15B . . .and the spring cap22.15A Fit the valve spring . . .
22.14B . . . and push onto the spring seat
using a socket22.14A . . . then fit the valve stem oil
seal . . .22.13 Slide the oil seal fitting sleeve down
the valve stem . . .
22.11 Inserting an exhaust valve into its
guide22.7 Inlet (1) and exhaust (2) valve
components
2A

REF
Overall length: *
Saloon models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4432 mm
Hatchback models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4352 mm
Overall width: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1876 mm
Overall height (unladen): *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1400 mm
Wheelbase: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2600 mm
Track:
Front: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1426 mm
Rear: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1423 mm
Ground clearance (minimum): *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .120 mm
Weights
Kerb weight: *
Dependent on model . . . . . . . . . . . . . . . . . . . . . . . . . .1098 ± 101 kg
Maximum gross vehicle weight: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Refer to VIN plate
Maximum roof rack load: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100 kg
Maximum towing hitch downward load: *
All models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75 kg
Maximum towing weight: *
Trailer with brakes . . . . . . . . . . . . . . . . . . . . . . . . . . . .1175 ± 175 kg
Trailer without brakes . . . . . . . . . . . . . . . . . . . . . . . . . . .550 ± 50 kg
* Exact details depend upon model and specification.
Refer to owners handbook.
Dimensions and Weights . . . . . . . . . . . . . . . . . .REF•1
Conversion Factors . . . . . . . . . . . . . . . . . . . . . . .REF•2
Buying Spare Parts . . . . . . . . . . . . . . . . . . . . . . .REF•3
Vehicle Identification . . . . . . . . . . . . . . . . . . . . . .REF•3
General Repair Procedures . . . . . . . . . . . . . . . . .REF•4
Jacking and Vehicle Support . . . . . . . . . . . . . . .REF•5Radio/cassette unit Anti-theft System . . . . . . . .REF•5
Tools and Working Facilities . . . . . . . . . . . . . . . .REF•6
MOT Test Checks . . . . . . . . . . . . . . . . . . . . . . . .REF•8
Fault Finding . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•12
Glossary of Technical Terms . . . . . . . . . . . . . . .REF•20
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .REF•25
Reference REF•1
Dimensions and Weights

REF•2Conversion Factors
Length (distance)Inches (in) 25.4 = Millimetres (mm) x 0.0394 = Inches (in)
Feet (ft) 0.305 = Metres (m) x 3.281 = Feet (ft)
Miles 1.609 = Kilometres (km) x 0.621 = Miles
Volume (capacity)Cubic inches (cu in; in3) x 16.387 = Cubic centimetres (cc; cm3) x 0.061 = Cubic inches (cu in; in3)
Imperial pints (Imp pt) x 0.568 = Litres (l) x 1.76 = Imperial pints (Imp pt)
Imperial quarts (Imp qt) x 1.137 = Litres (l) x 0.88 = Imperial quarts (Imp qt)
Imperial quarts (Imp qt) x 1.201 = US quarts (US qt) x 0.833 = Imperial quarts (Imp qt)
US quarts (US qt) x 0.946 = Litres (l) x 1.057 = US quarts (US qt)
Imperial gallons (Imp gal) x 4.546 = Litres (l) x 0.22 = Imperial gallons (Imp gal)
Imperial gallons (Imp gal) x 1.201 = US gallons (US gal) x 0.833 = Imperial gallons (Imp gal)
US gallons (US gal) x 3.785 = Litres (l) x 0.264 = US gallons (US gal)
Mass (weight)Ounces (oz) x 28.35 = Grams (g) x 0.035 = Ounces (oz)
Pounds (lb) x 0.454 = Kilograms (kg) x 2.205 = Pounds (lb)
ForceOunces-force (ozf; oz) x 0.278 = Newtons (N) x 3.6 = Ounces-force (ozf; oz)
Pounds-force (lbf; lb) x 4.448 = Newtons (N) x 0.225 = Pounds-force (lbf; lb)
Newtons (N) x 0.1 = Kilograms-force (kgf; kg) x 9.81 = Newtons (N)
PressurePounds-force per square inch x 0.070 = Kilograms-force per square x 14.223 = Pounds-force per square inch
(psi; lbf/in2; lb/in2) centimetre (kgf/cm2; kg/cm2) (psi; lbf/in2; lb/in2)
Pounds-force per square inch x 0.068 = Atmospheres (atm) x 14.696 = Pounds-force per square inch
(psi; lbf/in
2; lb/in2)(psi; lbf/in2; lb/in2)
Pounds-force per square inch x 0.069 = Bars x 14.5 = Pounds-force per square inch
(psi; lbf/in
2; lb/in2)(psi; lbf/in2; lb/in2)
Pounds-force per square inch x 6.895 = Kilopascals (kPa) x 0.145 = Pounds-force per square inch
(psi; lbf/in
2; lb/in2)(psi; lbf/in2; lb/in2)
Kilopascals (kPa) x 0.01 = Kilograms-force per square x 98.1 = Kilopascals (kPa)
centimetre (kgf/cm
2; kg/cm2)
Millibar (mbar) x 100 = Pascals (Pa) x 0.01 = Millibar (mbar)
Millibar (mbar) x 0.0145 = Pounds-force per square inch x 68.947 = Millibar (mbar)
(psi; lbf/in
2; lb/in2)
Millibar (mbar) x 0.75 = Millimetres of mercury (mmHg) x 1.333 = Millibar (mbar)
Millibar (mbar) x 0.401 = Inches of water (inH
2O) x 2.491 = Millibar (mbar)
Millimetres of mercury (mmHg) x 0.535 = Inches of water (inH
2O) x 1.868 = Millimetres of mercury (mmHg)
Inches of water (inH
2O) x 0.036 = Pounds-force per square inch x 27.68 = Inches of water (inH2O)
(psi; lbf/in2; lb/in2)
Torque (moment of force)Pounds-force inches (lbf in; lb in) x 1.152 = Kilograms-force centimetre x 0.868 = Pounds-force inches (lbf in; lb in)
(kgf cm; kg cm)
Pounds-force inches (lbf in; lb in) x 0.113 = Newton metres (Nm) x 8.85 = Pounds-force inches (lbf in; lb in)
Pounds-force inches (lbf in; lb in) x 0.083 = Pounds-force feet (lbf ft; lb ft) x 12 = Pounds-force inches (lbf in; lb in)
Pounds-force feet (lbf ft; lb ft) x 0.138 = Kilograms-force metres (kgf m; kg m) x 7.233 = Pounds-force feet (lbf ft; lb ft)
Pounds-force feet (lbf ft; lb ft) x 1.356 = Newton metres (Nm) x 0.738 = Pounds-force feet (lbf ft; lb ft)
Newton metres (Nm) x 0.102 = Kilograms-force metres (kgf m; kg m) x 9.804 = Newton metres (Nm)
PowerHorsepower (hp) x 745.7 = Watts (W) x 0.0013 = Horsepower (hp)
Velocity (speed)Miles per hour (miles/hr; mph) x 1.609 = Kilometres per hour (km/hr; kph) x 0.621 = Miles per hour (miles/hr; mph)
Fuel consumption*Miles per gallon (mpg) x 0.354 = Kilometres per litre (km/l) x 2.825 = Miles per gallon (mpg)
* It is common practice to convert from miles per gallon (mpg) to litres/100 kilometres (l/100km), where mpg x l/100 km = 282
TemperatureDegrees Fahrenheit = (°C x 1.8) + 32 Degrees Celsius (Degrees Centigrade; °C) = (°F - 32) x 0.56

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

Glossary of Technical Terms REF•21
REF
CamshaftA rotating shaft on which a series
of cam lobes operate the valve mechanisms.
The camshaft may be driven by gears, by
sprockets and chain or by sprockets and a
belt.
CanisterA container in an evaporative
emission control system; contains activated
charcoal granules to trap vapours from the
fuel system.
CarburettorA device which mixes fuel with
air in the proper proportions to provide a
desired power output from a spark ignition
internal combustion engine.
CastellatedResembling the parapets along
the top of a castle wall. For example, a
castellated balljoint stud nut.
CastorIn wheel alignment, the backward or
forward tilt of the steering axis. Castor is
positive when the steering axis is inclined
rearward at the top.Catalytic converterA silencer-like device in
the exhaust system which converts certain
pollutants in the exhaust gases into less
harmful substances.
CirclipA ring-shaped clip used to prevent
endwise movement of cylindrical parts and
shafts. An internal circlip is installed in a
groove in a housing; an external circlip fits into
a groove on the outside of a cylindrical piece
such as a shaft.
ClearanceThe amount of space between
two parts. For example, between a piston and
a cylinder, between a bearing and a journal,
etc.
Coil springA spiral of elastic steel found in
various sizes throughout a vehicle, for
example as a springing medium in the
suspension and in the valve train.
CompressionReduction in volume, and
increase in pressure and temperature, of a
gas, caused by squeezing it into a smaller
space.
Compression ratioThe relationship between
cylinder volume when the piston is at top
dead centre and cylinder volume when the
piston is at bottom dead centre.
Constant velocity (CV) jointA type of
universal joint that cancels out vibrations
caused by driving power being transmitted
through an angle.
Core plugA disc or cup-shaped metal device
inserted in a hole in a casting through which
core was removed when the casting was
formed. Also known as a freeze plug or
expansion plug.
CrankcaseThe lower part of the engine
block in which the crankshaft rotates.
CrankshaftThe main rotating member, or
shaft, running the length of the crankcase,
with offset “throws” to which the connecting
rods are attached.Crocodile clipSee Alligator clip
DDiagnostic codeCode numbers obtained by
accessing the diagnostic mode of an engine
management computer. This code can be
used to determine the area in the system
where a malfunction may be located.
Disc brakeA brake design incorporating a
rotating disc onto which brake pads are
squeezed. The resulting friction converts the
energy of a moving vehicle into heat.
Double-overhead cam (DOHC)An engine
that uses two overhead camshafts, usually
one for the intake valves and one for the
exhaust valves.
Drivebelt(s)The belt(s) used to drive
accessories such as the alternator, water
pump, power steering pump, air conditioning
compressor, etc. off the crankshaft pulley.
DriveshaftAny shaft used to transmit
motion. Commonly used when referring to the
axleshafts on a front wheel drive vehicle.
Drum brakeA type of brake using a drum-
shaped metal cylinder attached to the inner
surface of the wheel. When the brake pedal is
pressed, curved brake shoes with friction
linings press against the inside of the drum to
slow or stop the vehicle.
Castellated nut
Catalytic converter
Crankshaft assembly
Carburettor
Canister
Drum brake assembly
Accessory drivebelts
Driveshaft

REF•22Glossary of Technical Terms
EEGR valveA valve used to introduce exhaust
gases into the intake air stream.
Electronic control unit (ECU)A computer
which controls (for instance) ignition and fuel
injection systems, or an anti-lock braking
system. For more information refer to the
Haynes Automotive Electrical and Electronic
Systems Manual.
Electronic Fuel Injection (EFI)A computer
controlled fuel system that distributes fuel
through an injector located in each intake port
of the engine.
Emergency brakeA braking system,
independent of the main hydraulic system,
that can be used to slow or stop the vehicle if
the primary brakes fail, or to hold the vehicle
stationary even though the brake pedal isn’t
depressed. It usually consists of a hand lever
that actuates either front or rear brakes
mechanically through a series of cables and
linkages. Also known as a handbrake or
parking brake.
EndfloatThe amount of lengthwise
movement between two parts. As applied to a
crankshaft, the distance that the crankshaft
can move forward and back in the cylinder
block.
Engine management system (EMS)A
computer controlled system which manages
the fuel injection and the ignition systems in
an integrated fashion.
Exhaust manifoldA part with several
passages through which exhaust gases leave
the engine combustion chambers and enter
the exhaust pipe.
FFan clutchA viscous (fluid) drive coupling
device which permits variable engine fan
speeds in relation to engine speeds.Feeler bladeA thin strip or blade of hardened
steel, ground to an exact thickness, used to
check or measure clearances between parts.
Firing orderThe order in which the engine
cylinders fire, or deliver their power strokes,
beginning with the number one cylinder.
Flywheel A heavy spinning wheel in which
energy is absorbed and stored by means of
momentum. On cars, the flywheel is attached
to the crankshaft to smooth out firing
impulses.
Free playThe amount of travel before any
action takes place. The “looseness” in a
linkage, or an assembly of parts, between the
initial application of force and actual
movement. For example, the distance the
brake pedal moves before the pistons in the
master cylinder are actuated.
FuseAn electrical device which protects a
circuit against accidental overload. The typical
fuse contains a soft piece of metal which is
calibrated to melt at a predetermined current
flow (expressed as amps) and break the
circuit.
Fusible linkA circuit protection device
consisting of a conductor surrounded by
heat-resistant insulation. The conductor is
smaller than the wire it protects, so it acts as
the weakest link in the circuit. Unlike a blown
fuse, a failed fusible link must frequently be
cut from the wire for replacement.
GGapThe distance the spark must travel in
jumping from the centre electrode to the sideelectrode in a spark plug. Also refers to the
spacing between the points in a contact
breaker assembly in a conventional points-
type ignition, or to the distance between the
reluctor or rotor and the pickup coil in an
electronic ignition.
GasketAny thin, soft material - usually cork,
cardboard, asbestos or soft metal - installed
between two metal surfaces to ensure a good
seal. For instance, the cylinder head gasket
seals the joint between the block and the
cylinder head.
GaugeAn instrument panel display used to
monitor engine conditions. A gauge with a
movable pointer on a dial or a fixed scale is an
analogue gauge. A gauge with a numerical
readout is called a digital gauge.
HHalfshaftA rotating shaft that transmits
power from the final drive unit to a drive
wheel, usually when referring to a live rear
axle.
Harmonic balancerA device designed to
reduce torsion or twisting vibration in the
crankshaft. May be incorporated in the
crankshaft pulley. Also known as a vibration
damper.
HoneAn abrasive tool for correcting small
irregularities or differences in diameter in an
engine cylinder, brake cylinder, etc.
Hydraulic tappetA tappet that utilises
hydraulic pressure from the engine’s
lubrication system to maintain zero clearance
(constant contact with both camshaft and
valve stem). Automatically adjusts to variation
in valve stem length. Hydraulic tappets also
reduce valve noise.
IIgnition timingThe moment at which the
spark plug fires, usually expressed in the
number of crankshaft degrees before the
piston reaches the top of its stroke.
Inlet manifoldA tube or housing with
passages through which flows the air-fuel
mixture (carburettor vehicles and vehicles with
throttle body injection) or air only (port fuel-
injected vehicles) to the port openings in the
cylinder head.
Exhaust manifold
Feeler blade
Adjusting spark plug gap
Gasket
EGR valve