1983 FIAT UNO oil filter

2 Engine oil and filter
1
1The engine oil level should be checked at
the weekly service (see “Routine
Maintenance”). Preferably check the level
cold, first thing in the morning or if the engine
has been running, allow at least ten minutes
to elapse after switching off to permit the oil to
drain.
2Withdraw the dipstick, wipe it clean on
non-fluffy material, re-insert it and then
withdraw it for the second time (photo).
3The oil level should be between the MIN
and MAX marks. If not, top up with specified
oil to the MAX mark. Pour the oil slowlythrough the filler orifice on the rocker cover.
To raise the oil level from MIN to MAX will
require approximately 1.1 litre (2.0 pints)
(photos).
4At the intervals specified in “Routine
Maintenance” the oil and filter should be
renewed.
5Have the engine at normal operating
temperature, remove the oil filler cap.
6Place a suitable container under the sump
pan. Unscrew and remove the oil drain plug
and allow the oil to drain (photo).
7While the oil is draining, unscrew and
discard the oil filter. To unscrew the filter, a
filter or chain wrench will normally be
required. If such a tool is not available, drive a
long screwdriver through the oil tester casing
and use it as a lever to unscrew the filter
cartridge.
8Smear the rubber sealing ring of the new oil
filter with oil and screw into position using
hand pressure only (photo).
9Refit the drain plug and refill the engine with
the correct quantity and grade of oil.
10Start the engine. It will take two or three
seconds for the oil warning lamp to go out.
This is normal and is due to the time taken for
the new filter to fill with oil.
11Switch off, check for leaks and check the
oil level, topping up if necessary.
3 Crankcase ventilation
system
1
1This system is designed to draw oil fumes
and blow-by gas (which has passed the piston
rings) from the crankcase and draw it into the
intake manifold when it will then be burned
during the normal combustion process.
2Regularly check the security of the system
hoses which run from the rocker cover or
crankcase breather unit (photo).
3Periodically, detach the hoses and clean
them out with paraffin and a brush or rag pull
through.
4Evidence of sludge or emulsified oil within
the hoses or inside the oil filler cap will
indicate that the engine is running too cool
particularly if the car is used mainly for short
journeys where the engine never reaches full
working temperature.
4 Major operations possible
without removing engine
from car
1The following work can be carried out without
the need to remove the engine from the car.
903 cc engine
Valve clearances - checking and adjusting
Timing chain and sprockets - removal and
refitting
1•8 Engine – general
3.2 Crankcase vent hose (1116 cc)Fig. 1.5 Sectional view of oil filter. Bypass
valve arrowed (Sec 2)2.8 Screwing on the oil filter (903 cc)
2.6 Engine sump drain plug
2.3B Topping up engine oil (1116 cc)2.3A Typical dipstick markings2.2 Withdrawing engine oil dipstick
(1116 cc)

31Support the weight of the transmission
and withdraw it in a straight line from the
engine.
14 Engine- dismantling (general)
1Stand the engine on a strong bench at a
suitable working height. Failing this, it can be
dismantled on the floor, but at least stand it
on a sheet of hardboard.
2During the dismantling process, the
greatest care should be taken to keep the
exposed parts free from dirt. As the engine is
stripped, clean each part in a bath of paraffin.
3Never immerse parts with oilways in
paraffin, e.g. the crankshaft, but to clean,
wipe down carefully with a paraffin dampened
rag. Oilways can be cleaned out with a piece
of wire. If an air line is available, all parts can
be blown dry and the oilways blown through
as an added precaution.
4Re-use of old gaskets is false economy and
can give rise to oil and water leaks, if nothing
worse. To avoid the possibility of trouble after
the engine has been reassembled always use
new gaskets throughout.
5To strip the engine, it is best to work from
the top downwards. The engine oil sump
provides a firm base on which the engine can
be supported in an upright position. When the
stage is reached where the pistons are to be
removed, turn the engine on its side. Turn the
block upside down to remove the crankshaft.
6Wherever possible, replace nuts, bolts and
washers finger-tight from wherever they were
removed. This helps avoid later loss and
muddle. If they cannot be replaced then lay
them out in such a fashion that it is clear from
where they came.
15 Engine- removing ancillary
components
1Before dismantling the engine, remove the
engine ancillary components.
Carburettor (Chapter 3)
Thermostat housing (Chapter 2)
Alternator (Chapter 9)
Coolant pump (Chapter 2)
Distributor (Chapter 4)
Exhaust manifold (Chapter 3)
Fuel pump (Chapter 3)
Oil filter cartridge (Section 2 this Chapter)
Clutch (Chapter 5)
903 cc engine 1•15
Fig. 1.21 Camshaft and rocker gear components (Sec 16)
Fig. 1.22 Cylinder head, block and crankcase (Sec 16)
1 Camshaft bush
lockbolt
2 Washer
3 Camshaft front
bearing
4 Exhaust valve
5 Spring cap
6 Valve guide
7 Adjuster screw8 Rocker arm
9 Thrust washer
10 Circlip
11 Locknut
12 Washer
13 Locknut
14 Pedestal
15 Rocker arm
16 Plug17 Rocker shaft
18 Coil spring
19 Stud
20 Split collets
21 Spring cap
22 Valve guide
23 Outer valve spring
24 Inner valve spring
25 Spring seat26 Inlet valve
27 Camshaft bearing
28 Camshaft bearing
29 Camshaft
30 Locating dowel
31 Cam follower
32 Pushrod
33 Washer
1 Washer
2 Cylinder head bolt
3 Gasket
4 Rocker cover
gasket
5 Rocker cover6 Washer
7 Plate
8 Nut
9 Stud
10 Plug
11 Cylinder head12 Plug
13 Cylinder head bolt
14 Washer
15 Dowel
16 Plug
17 Plug18 Dowel
19 Block/crankcase
20 Plug
21 Plug
22 Bolt
23 Plug
1
Do not throw the old
gaskets away as it
sometimes happens that an
immediate replacement
cannot be found and the old gasket is
then very useful as a template. Hang
up the gaskets on a suitable nail or
hook as they are removed.

Oil seals and gaskets
49It is recommended that all gaskets and oil
seals are renewed at major engine overhaul.
Sockets are useful for removing or refitting oil
seals. An arrow is moulded onto some seals
to indicate the rotational direction of the
component which it serves. Make sure that
the seal is fitted the correct way round to
comply with the arrow.
19 Engine- reassembly (general)
1To ensure maximum life with minimum
trouble from a rebuilt engine, not only must
every part be correctly assembled, but
everything must be spotlessly clean, all the
oilways must be clear, locking washers and
spring washers must always be fitted where
indicated and all bearing and other working
surfaces must be thoroughly lubricated during
assembly. Before assembly begins renew any
bolts or studs whose threads are in any way
damaged; whenever possible use new spring
washers.
2Apart from your normal tools, a supply of
non-fluffy rag, an oil can filled with engine oil,
a supply of new spring washers, a set of new
gaskets and a torque wrench should be
gathered together.
20 Engine-
complete reassembly
4
Crankshaft and main bearings
1With the cylinder block inverted on the
bench, wipe out the crankcase shell bearing
seats and fit the half shells so that their tabs
engage in the notches (photo).
2Stick the semi-circular thrust washers either
side of the centre bearing in the crankcase
using thick grease. Make sure that the oil
grooves are visible when the washers are
fitted (photo).
3If the original bearing shells are being
refitted, make sure that they are returned to
their original positions.
4Liberally oil the bearing shells and lower the
crankshaft into position. Make sure that it is
the correct way round (photos).
5Wipe out the main bearing caps and fit the
bearing shells into them.
6Oil the crankshaft journals and fit the main
bearing caps, the correct way round and in
proper sequence (photo).
7Replace the main bearing cap bolts and
screw them up finger-tight.
8Test the crankshaft for freedom of rotation.
Should it be very stiff to turn, or possess high
spots, a most careful inspection must be
made, preferably by a skilled mechanic with a
1•20 903 cc engine
20.4B Lowering crankshaft into
position20.4A Oiling main bearing shells
20.2 Crankshaft thrust washer20.1 Fitting a main bearing shell
Fig. 1.27 Exploded view of oil pump (Sec 18)
1 Bolt
2 Bolt
3 Washers
4 Washer
5 Spring
6 Drive gear
7 Top housing
8 Driven gear
9 Plate
10 Pressure relief valve
11 Lower housing and
oil pick-up
12 Filter screen

17Screw in the camshaft front bearing
lockscrew (photo).
Oil pump
18Refit the oil pump as described in Sec-
tion 10.
Timing chain and sprockets
19Fit the timing chain and sprockets as
described in Section 6. Fit the Woodruff key
to the crankshaft nose.
20Using a new gasket, fit the timing chain
cover, but leave the bolts finger tight (photo).
21Apply grease to the lips of the timing
cover oil seal and then push the crankshaft
pulley into position.
22Move the timing cover if necessary so that
the pulley hub is centralised in the oil seal and
then tighten the cover bolts.
23Screw on the crankshaft pulley nut and
tighten to the specified torque (photo).
Piston/connecting rods
24Fit these as described in Section 9.
Sump pan
25Fit the sump pan as described in Sec-
tion 8.
Cylinder head
26Stand the engine upright and fit the
cylinder head as described in Section 7.
27Insert the pushrods in their original fitted
order.
28With the rocker arm adjuster screws fully
unscrewed, locate the rocker gear and screw
on the fixing nuts.
29Adjust the valve clearances as described
in Section 5.
30Locate a new gasket in position and fit the
rocker cover (photo).
31Screw on a new oil filter (Section 2).
21 Engine- refitting ancillary
components
1Refer to Chapter 5 and refit the clutch,
making sure to centralise the driven plate.
2Fit the coolant pump as described in
Chapter 2. Fit the thermostat housing if it was
removed noting the air cleaner mounting
bracket on the housing studs.
3Fit the alternator and drivebelt as described
in Chapter 9.
4Refer to Chapter 3 and fit the exhaust
manifold and hot air collector, the carburettor
and spacer and the fuel pump.
5Fit the distributor as described in Chapter
4. Fit the oil dipstick guide tube (photos).
22 Engine/transmission-
reconnection
1
1Support the weight of the transmission and
offer it squarely to the engine. The splined
input shaft should pass easily through the hub
of the driven plate, provided the plate has
been centralised as described in Chapter 5. It
may be necessary to align the splines with the
hub grooves, in which case have an assistant
turn the crankshaft pulley nut. The alignment
dowels will make the connection stiff, so
drawing the engine and transmission together
with two connecting bolts will ease it.
2Once the engine and transmission are fully
engaged, insert and tighten all the connecting
bolts. Locate the lifting eyes.
3Bolt on the flywheel housing cover plate
and the mounting brackets.
4Bolt on the starter motor.
23 Engine/transmission-
refitting
3
1The refitting operations are reversals of
those described in Section 13.
2Observe the following special points.
3Tighten the engine mounting and front
suspension (disconnected) bolts to the
specified torque when the hoist has been
1•22 903 cc engine
21.5B Dipstick guide tube support21.5A Dipstick guide tube20.30 Rocker cover nut and thrust plate
20.23 Tightening crankshaft pulley nut20.20 Timing cover20.17 Camshaft front bearing lockscrew
Hold the crankshaft against
rotation either by jamming
the starter ring gear or by
placing a block of wood
between a crankshaft web and the
inside of the crankcase.

5In practice, if several shims have to be
changed, they can often be interchanged, so
avoiding the necessity of having to buy more
new shims than is necessary.
6If more than two or three valve clearances
are found to be incorrect, it will be more
convenient to remove the camshaft carrier for
easier removal of the shims.
7Where no clearance can be measured, even
with the thinnest available shim in position,
the valve will have to be removed and the end
of its stem ground off squarely. This will
reduce its overall length by the minimum
amount to provide a clearance. This job
should be entrusted to your dealer as it is
important to keep the end of the valve stem
square.
8On completion, refit the camshaft cover and
gasket.
27 Camshaft and camshaft
carrier- removal and refitting
3
1Disconnect the battery.
2Remove the air cleaner (see Chapter 3).
3Disconnect the fuel filter hose from the fuel
pump and tie it back, out of the way.
4Identify and then disconnect any electrical
leads which must be moved away to enable
the camshaft cover to be withdrawn.
5Identify and disconnect any vacuum gases
which must be moved away to enable the
camshaft cover to be withdrawn.
6Unscrew the securing nuts and remove the
camshaft cover.
7Turn the crankshaft pulley nut until No. 4
piston is at TDC. This can be established as
described in Section 28.
8Unbolt and remove the timing belt cover.
9Check that the timing mark on the camshaft
sprocket is aligned with, and adjacent to the
pointer on the timing belt cover backplate.
10Restrain the timing belt with the hand and
release but do not remove the camshaft
sprocket bolt. Release the belt tensioner
pulley by slackening the pulley centre nut.
Push the timing belt evenly from the
sprockets, noting which way round the belt isfitted if it is to be completely removed. The
lettering on the belt is normally legible from
the crankshaft pulley end of the engine when
the belt is as originally fitted.
11Unbolt the camshaft carrier and lift it
sufficiently from the cylinder head to break the
seal of the mating faces. Note: It is important
not to allow the cam followers to pull out; they
must be retained in their original locations.
This can be done if the carrier is raised very
slowly, until the fingers can be inserted to
prise the cam followers onto their respective
valve spring retainers. It is unlikely that the
valve clearance adjusting shims will be
displaced from their recesses in the cam
followers because of the suction of the
lubricating oil, but watch that this does not
happen; the shims must also be retained in
their originally fitted sequence.
12Remove the previously loosened
camshaft sprocket bolt and take the sprocket
from the camshaft.
13Unbolt and remove the camshaft end
cover with its gasket. Withdraw the camshaft
(photos).
14Refitting is a reversal of the removal
process, but observe the following points.
15Use new gaskets.
16Retain the cam followers and shims in
their bores in the camshaft carrier with thick
grease; they must not be allowed to drop out
when the carrier is lowered onto the cylinder
head.
17If the crankshaft or camshaft have been
moved from their set positions, re-align the
sprocket timing mark with the pointer on the
belt cover and the crankshaft pulley or
flywheel with the TDC mark. This must be
observed otherwise the valves may impinge
upon the piston crowns when the camshaft
lobes compress any of the valve springs
during bolting down of the carrier.
18Screw in the carrier bolts and tighten
them to the specified torque (photo).
19Refit and tension the timing belt as
described in Section 28.
20Refit the camshaft cover and gasket.
21Refit the hose and air cleaner.
22Reconnect the battery.
28 Timing belt- renewal
3
1Set No. 4 piston at TDC. Do this by turning
the crankshaft pulley nut or by jacking up a
front roadwheel, engaging a gear and turning
the wheel until the mark on the flywheel is
opposite to the TDC mark on the flywheel
bellhousing aperture. Remove No. 4 spark
plug, place a finger over the plug hole and feel
the compression being generated as the
crankshaft is rotated and the piston rises up
the cylinder bore.
2On some models the TDC marks on the
crankshaft pulley and belt cover may be
visible and can be used instead.
3Remove the alternator drivebelt (Chapter 2,
Section 8). Unbolt and remove the timing belt
cover.
4Check that the timing mark on the camshaft
sprocket is aligned with the pointer on the belt
cover backing plate (photo).
5Slacken the nut in the centre of the
tensioner pulley and push in on the support to
release the tension on the belt, then retighten
the nut. Slide the drivebelt off the pulleys.
6Check that the crankshaft and camshaft
pulleys have not been moved from their
previously aligned positions.
7To check that the auxiliary shaft sprocket
has not moved, take off the distributor cap
and check that the contact end of the rotor
arm is aligned with No. 4 HT lead contact in
the cap.
1•24 1116 cc and 1301 cc engine
28.4 Camshaft sprocket alignment marks
27.18 Tightening a camshaft carrier bolt27.13B Withdrawing camshaft from carrier27.13A Removing camshaft end cover

head gasket must be fitted (ALTO visible) so
that the oil pressure hole in the block is
central in the copper ringed cut-out in the
gasket (photos). Make sure that the gasket
surfaces on head and block are perfectly
clean and free from oil, otherwise the heat
sealing (polymerisation) process of the gasket
cannot take place.
22Tighten the cylinder head nuts and bolts
to the specified torque, in the sequence
shown in Fig. 1.30. Follow the procedure very
carefully owing to the special type (ASTADUR)
of gasket used which hardens in use. Always
keep a new cylinder head gasket in its
nylon cover until just before it is required for
use.
23Oil the cylinder head bolts and
washers and allow them to drain for thirty
minutes.
24Tighten the bolts in the following
stages:
Stage 1 20 Nm (15 lbf ft)
Stage 2 40 Nm (30 lbf ft)
Stage 3 Through 90º
Stage 4 Through 90º (photo)
Retightening the bolts after a running-in
mileage is not required.
25Fit the timing belt (Section 28).
26Check the valve clearances (Section 26)
after the camshaft carrier has been fitted
(Section 27).
27Bolt on the camshaft carrier cover.
28Reconnect all hoses, leads and controls.
29Reconnect the battery and refill the
cooling system.
30 Sump pan-
removal and refitting
1
1Position the car over an inspection pit or
raise the front wheels on ramps.
2Disconnect the battery.
3Drain the engine oil. Unbolt and remove the
flywheel housing lower cover plate.
4Unbolt the sump pan and remove it
together with its gasket.
5Refitting is a reversal of removal. Always
use a new gasket locating it on clean mating
flanges and tighten the fixing bolts evenly and
progressively (photo).
6Fill the engine with oil and reconnect the
battery.
31 Oil pump-
removal and refitting
1
1Remove the sump pan as described in the
preceding Section.
2Unbolt the oil pump and withdraw it
complete with driveshaft.
3Use a new gasket when refitting the pump
and prime the pump by pouring engine oil
through the pick-up filter screen (photo).
32 Pistons/connecting rod-
removal and refitting
3
1Remove the sump pan and the oil pump as
described in Sections 30 and 31.
1•26 1116 cc and 1301 cc engine
Fig. 1.31 Piston/connecting rod assembly
diagram (Sec 32)
1 Matching numbers
2 Gudgeon pin offset
3 Auxiliary shaft
Arrow indicates direction of rotation of
crankshaft viewed from timing belt end
29.24 Tightening a cylinder head bolt
through 90º using a protractor
31.3 Bolting on the oil pump30.5 Locating the sump pan gasket
29.21C Lowering cylinder onto block29.21B Cylinder head gasket in position -
cylinder block drain plug arrowed29.21A Cylinder head gasket top face
marking

6Remove the spring seat (photo).
7Discard the valve stem oil seal and fit a new
one (photo).
8Remove the remaining valves in a similar
way and keep the components in their
originally fitted sequence.
9Reassembly is a reversal of removal. Refit
the components to their original positions, but
renew the valve springs if their free length is
less than that of a new spring or if the
springs have been in operation for more than
80 000 km (50 000 miles).
10The original valve clearance adjusting
shims will no longer provide the correct
clearances if the valves have been ground in
or the seats recut. Only where dismantling of
a valve was carried out to renew a spring is
there any purpose in returning the shims to
their original locations. Try to obtain the loan
of eight thin shims from your dealer and insert
them into the tappets (cam followers) before
assembling the cam followers to the carrier,
where they should be retained with thick
grease (photo).
11Fit the camshaft carrier, complete with
cam followers and shims to the cylinder head.
12Adjust the valve clearances as described
in Section 26.
40 Examination and renovation
4
1The procedures are similar to those
described in Section 18 covering the
following:
Cylinder block and crankcase
Crankshaft and bearings
Pistons and piston rings
Flywheel
2The following additional items must also be
examined.
Oil pump
3Carefully, clamp the pump housing in a
vice, shaft downwards.
4Take off the pump cover, with the suction
pipe. This will release the oil pressure relief
valve inside. Also inside is a filter.
5Remove the internal cover plate.6Take out the driveshaft and the gears.
7Clean and examine all the parts. Measure
the clearances against the Specifications. The
end clearance is measured by putting a
straight-edge across the cover face.
8The oil pump should only need
replacements after very long mileage, when
the rest of the engine is showing great signs
of wear.
9The length of a new gear can be measured
against the old gear to see if a new gear will
restore the end clearance to the Specifica-
tions. Otherwise the housing must be
changed.
10The driven gear shaft is mounted in the
housing with an interference fit. If there is any
slackness, a new housing (which will come
with shaft fitted) must be used.
11The oil pump shares its drive with the
distributor.
Camshaft, cam followers and
shims
12The camshaft journals and cams should
be smooth, without grooves or scores.
13Wear in the camshaft carrier bearings can
only be rectified by renewal of the carrier.
14Cam follower wear is usually very small
and when they show slackness in their bores,
it is probably the light alloy of the camshaft
carrier which has worn.
15Always measure the thickness of the valve
clearance shims using a metric micrometer.
Any grooving or wear marks in the shims
should be rectified by renewal with ones of
similar thickness.
Auxiliary shaft
16The shaft journals, the fuel pump
eccentric, and the drivegear for the distributor
and oil pump should be smooth and shiny. If
not, the shaft will have to be renewed.
17The bushes should still be tight in the
cylinder block, their oil holes lined up with
those in the block.
18Measure the bearing clearance. If
excessive, the bushes will have to be
renewed. They are a press fit, and require
reaming with a special reamer after fitting.
This is a job best done by a Fiat agent with the
special tools.
19Ensure the new bushes are fitted with the
oil holes lined up.
20Also check the driven gear and its bush.
21It is recommended a new oil seal is fitted
in the endplate. Hold the shaft in a vice, and
remove the pulley. Fit the new oil seal in the
endplate, lips inwards.
Timing belt tensioner
22Check the bearing revolves smoothly and
freely, and has no play. Do not immerse it in
cleaning fluid, as it is partially sealed. Wipe
the outside, and then smear in some new
general purpose grease.
23The action of the spring will have been felt
when the belt was taken off. It should be
cleaned, and oiled, to prevent seizure through
dirt and rust.
24Note the circlip on the engine right-hand
mounting bracket. This retains the timing belt
tensioner plunger.
1116 cc and 1301 cc engine 1•29
39.6 Valve spring seat39.5 Removing a valve39.4B Double valve springs
39.10 Cam followers fitted to camshaft
carrier39.7 Valve stem oil seal
1

plate to the crankcase, using a new gasket
(photos).
11Fit the belt sprocket and partially tighten
its bolt. Then, using an oil filter strap wrench
or similar device to hold the sprocket against
rotation, tighten the bolt to the specified
torque. Take care not to damage the teeth of
the sprocket, which is of fibre construction
(photo).
Oil sump, sump pan and
breather
12Fit the oil drain pipe by tapping it into
place, squarely in its hole in the crankcase.
Tighten its retaining bolt (photo).
13Bolt up the oil pump, using a new gasket
at its mounting flange (photo).14Fit the sump (using a new gasket) and
tighten the securing screws to the specified
torque. Note the reinforcement washers
(photo).
15Insert the oil pump/driveshaft into the
distributor hole. This does not have to be
specially positioned as the distributor is
splined to the shaft and can be set by moving
its location in the splines (refer to Chapter 4)
(photo).
16Push the breather into its crankcase
recess and tighten its securing bolt (photos).Flywheel, crankshaft sprocket
and pulley
17Make sure that the flywheel-to-crankshaft
mounting flange surfaces are clean. Althoughthe bolt holes have unequal distances
between them, it is possible to fit the flywheel
in one of two alternative positions at 180º
difference. Therefore if the original flywheel is
being refitted, align the marks made before
removal.
18If a new flywheel is being fitted, or if
alignment marks were not made before
dismantling, set No. 1 position at TDC
(crankshaft front Woodruff key pointing
vertically). Fit the flywheel to its mounting
flange so that its timing dimple is uppermost
and in alignment with the relative position of
the TDC mark on the flywheel housing
inspection window.
19Insert the bolts and tighten them to the
specified torque, jamming the ring gear to
1116 cc and 1301 cc engine 1•31
42.11 Tightening camshaft sprocket bolt.
Note sprocket locking device42.10B Tightening auxiliary shaft end plate
bolt42.10A Auxiliary shaft end plate and
gasket
42.16B Crankcase breather and retaining
bolt42.16A Crankcase breather seal42.15 Fitting oil pump driveshaft
42.14 Tightening sump pan bolt42.13 Locating oil pump and gasket42.12 Tightening oil drain pipe bolt
1