check engine FIAT UNO 1983 Service Manual PDF

6Fit the main bearing caps in their numbered
sequence and the correct way round (photo).
7Clean the threads of the main bearing cap
bolts, lightly oil them and screw them in
finger-tight. Tighten all bolts progressively to
the specified torque, then check that the
crankshaft turns smoothly and evenly
(photos).
8Now check the crankshaft endfloat. Do this
using a dial gauge or feeler blades inserted
between the machined shoulder of a journal
and the side of the bearing cap (photo). Move
the crankshaft fully in one direction and then
the other to ensure that full movement is
obtained. If the endfloat is outside the
specified tolerance and new bearing shellshave been fitted, then a fault must have
occurred during crankshaft regrinding.
9Fit a new oil seal to the crankshaft rear oil
seal retainer. Apply grease to the seal lips. A
conventional gasket is not used at the oil seal
joint face but a 3.0 mm diameter bead of RTV
silicone instant gasket must be applied
to a clean surface as shown in Fig. 13.9
(photo).
10Bolt the retainer into position. One hour at
least must be allowed for the RTV to cure
before oil contacts it.
11Turn the engine on its side and fit the
piston/connecting rods as described in
sub-Section B.
12Fit a new oil seal to the oil pump, oil theseal lips and bolt on the pump using a new
joint gasket (photos).
13Use a new sealing washer and fit the oil
pick-up/filter screen assembly.
14Fit the engine rear plate and then the
flywheel on its mounting flange. Apply
thread-locking fluid to (clean) bolt threads and
screw in the bolts to the specified torque
(photo). Hold the flywheel against rotation by
locking the starter ring gear with a suitable
tool.
15Fit the sump pan as described in
sub-Section B.
16Fit the crankshaft sprocket so that the
timing mark is visible. Lock the flywheel
starter ring gear teeth, and screw in and
Supplement: Revisions and information on later models 13•31
5D.7B Angle-tightening a main bearing cap
bolt5D.7A Initial tightening of a main bearing
cap bolt5D.6 Fitting a main bearing cap
5D.14 Tightening a flywheel bolt5D.12B Tightening an oil pump bolt5D.12A Oil pump gasket
5D.9 Fitting crankshaft rear oil seal
retainerFig. 13.9 Application area for silicone
gasket on crankshaft rear oil seal retainer
(Sec 5D)5D.8 Checking crankshaft endfloat using a
dial gauge
13

separately, after the ten main bolts (see
Fig. 13.13).
Piston rings
14The piston rings comprise two
compression rings marked TOP, and an oil
control ring.
15Cross-sections and fitting details are
shown in Fig. 13.14.
Engine mountings - renewal
16The operations are essentially as
described in Section 33 of Chapter 1, but note
the design and fixings of the individual
mountings used on the turbocharged engine
(photos).
Timing belt - renewal#
17The operations described in Chapter 1,
Section 28 generally apply, but the following
differences should be noted.18Remove the engine compartment
right-hand shield. This is secured by plastic
clips. To remove a clip, push out its centre
pin.
19The TDC sensor must be unbolted to
provide room to remove and refit the timing
belt, which can be carried out without
having to remove the crankshaft pulley
(photos).
20The belt tensioner on later versions
does not incorporate a spring, but is of
eccentric centre bolt hole type. Have the
pulley bolt released, and tension the belt by
turning the pulley using a pin wrench or
circlip pliers in the two holes provided.
Keep the tension applied while the lockbolt
is tightened. Turn the crankshaft through
two complete turns, and then check the belt
tension. With moderate finger and thumb
pressure, the belt should just twist through90º when gripped at the mid-point of its
longest run (photo). Note: This procedure
serves only as a rough guide to setting the
belt tension - having it checked by a FIAT
dealer at the earliest opportunity is
recommended.
Oil pump drivegear cover plate
21Due to the fact that the distributor is
driven from the end of the camshaft, the oil
pump gear does not have an extension to
drive the distributor, which would be the case
if it was mounted on the crankcase.
22The crankcase aperture is therefore
covered by a plate and gasket, together with a
wiring clip (photo).
Supplement: Revisions and information on later models 13•35
6B.13 Two of the four additional cylinder
head bolts (arrowed)
Fig. 13.14 Piston ring arrangement on the
1301 cc Turbo ie engine (Sec 6B)Fig. 13.13 Cylinder head bolt tightening
sequence on the 1301 cc Turbo ie engine
(Sec 6B)
6B.22 Distributor drive hole cover plate
(arrowed)6B.20 Belt tensioner pulley locknut
(arrowed)6B.19B Removing the timing belt
6B.19A Removing the TDC sensor6B.16B Engine/transmission right-hand
mounting6B.16A Engine/transmission centre
mounting
13

Engine oil cooler -
removal and refittingÁ
23The oil cooler is mounted behind the front
bumper/spoiler (photo).
24Disconnect the oil flow and return hoses,
either from the cooler or the oil filter cartridge
mounting base. Be prepared for some
leakage of oil (photos).
25Unscrew the mounting bolts and remove
the oil cooler heat exchanger (photo).
26When refitting, make sure that the banjo
union sealing washers are in good condition.
PART C: ENGINE REMOVAL,
DISMANTLING, REASSEMBLY
AND REFITTING
Engine/transmission -
removal and separation
#
Warning: Refer to the beginning
of Section 9 before starting any
work.
1Refer to Chapter 1, Section 35, and carry
out the operations described in paragraphs 1
to 11.
2Disconnect the excessive air pressure
switch from the inlet manifold.
3Disconnect the ducts and remove the
airflow meter.
4Disconnect the leads from the spark plugs
and the distributor LT connector, and unbolt
and remove the distributor from the rear end
of the camshaft carrier.
5Disconnect the fuel return hose from the
pressure regulator. 6Disconnect the fuel inlet hose from the
injector rail.
7Disconnect the wiring plugs from the fuel
injectors.
8Disconnect the leads from the oil pressure
sender unit, the low oil pressure switch and
the coolant temperature switch.
9Remove the hose/pipe assemblies from the
intercooler.
10Disconnect the throttle control rod at the
balljoint.
11Disconnect the hoses and ducts from the
turbocharger and the mechanical bypass
valve.
12Disconnect the leads from the engine
speed and anti-knock sensors.
13Raise the front of the car and support it
securely. As the engine/transmission will
eventually be lowered to the floor, make sure
that there is sufficient clearance under the
front end for the assembly to be withdrawn. If
the car is over an inspection pit, then the car
need only be raised enough to lift the
roadwheels from the floor.
14Remove the front roadwheels.
15Disconnect the transmission earth cable.
16Working under the car, remove the engine
shields from under the wheel arches.
17Remove the engine oil cooler, and the
intercooler.
18Unscrew the fixing screws and disconnect
the driveshafts from the flanges at the
transmission final drive. The right-hand
driveshaft will not release until the upper bolt
on the suspension strut-to-hub carrier clamphas been removed, and the hub assembly
tilted downwards.
19Disconnect the exhaust downpipe from
the manifold, and then remove the front
section of the exhaust system.
20Disconnect the coolant return pipe from
the turbocharger.
21Disconnect the gearchange control rods
from the transmission selector rod. Do this by
unscrewing the self-locking nut from the bolt
which connects the clevis fork.
22Attach suitable lifting gear to the engine
lifting eyes, and take the weight of the
engine/transmission.
23Disconnect the left-front, centre-rear and
the right-hand engine/transmission mountings.
Do this by removing the bolts from the
diamond-shaped mounting plates there is no
need to disturb the flexible mounting centre
bolts.
24Lower the engine/transmission to the floor
and withdraw it from under the car.
25Carry out the operations described in
Chapter 1, Section 35, paragraphs 27 to 31.
Engine dismantling and
reassembly
26The operations are essentially as
described for the 1301 cc engine in Chapter 1,
but reference must be made to Sections 9
and 10 of this Chapter for the procedures for
removing and refitting the components of the
fuel injection, turbocharger and ignition
systems.
Engine/transmission -
reconnection and refitting
27The operations are a reversal of those
described in paragraphs 1 to 25, but
otherwise the following (photo).
a) Tighten all nuts and bolts to the specified
torque.
b) Use a new gasket at the exhaust
downpipe-to-manifold flange.
c) Check and adjust the clutch pedal travel.
d) Refill the cooling system.
e) Refill the engine and transmission with oil.
f) Reconnect the battery, negative lead
last.
13•36 Supplement: Revisions and information on later models
6C.27 Filling the engine with oil6B.25 Oil cooler mounting bolts (arrowed)
6B.24B Connections at oil filter cartridge
mounting base6B.24A Oil cooler pipe connection
(arrowed)6B.23 Oil cooler

Initial start-up after major
overhaul
28Refer to Chapter 1, Section 45, but note
that an oil pressure gauge is fitted to indicate
oil pressure.
29Check the ignition static timing as
described in Section 10.
30Check the engine idle speed and CO level
as described in Section 9.
7 Engine-
1372 cc ie and 1372 cc
Turbo ie
PART A: GENERAL
Description
1The 1372 cc engine is similar in design to
the OHC engine fitted to the FIAT Tipo
variants. The engine is of four-cylinder, in-line,
overhead camshaft type, mounted
transversely at the front of the vehicle.
2The crankshaft runs in five main bearings.
Thrustwashers are fitted to the rear (flywheel
end) main bearing in order to control
crankshaft endfloat.
3The connecting rods are attached to the
crankshaft by horizontally split shell-type
big-end bearings. The pistons are attached to
the connecting rods by fully-floating gudgeon
pins which are secured by circlips. The
aluminium alloy pistons are fitted with three
piston rings: two compression rings and an oil
control ring.
4The camshaft is driven by a toothed belt
and operates the valves via bucket and shim
type cam followers. The camshaft is located in
a separate housing on top of the cylinder
head.
5The inlet and exhaust valves are each
closed by double valve springs, and operate
in guides pressed into the cylinder head.
6The auxiliary shaft, which is also driven by
the toothed belt, drives the oil pump.
7Lubrication is by means of a gear type
pump which draws oil through a strainer
located in the sump, and forces it through a
full-flow filter into the engine oil galleries fromwhere it is distributed to the crankshaft,
camshaft and auxiliary shaft. The big-end
bearings are supplied with oil via internal
drillings in the crankshaft. The undersides of
the pistons are cooled by oil spray nozzles
located in each main bearing location in the
crankcase.
8A crankcase ventilation system is
employed, whereby piston blow-by gases are
drawn via an oil separator into the air cleaner,
from where they are drawn into the inlet
manifold and re-burnt with fresh air/fuel
mixture.
9The 1372 cc ie engine is fitted with a Bosch
Mono-Jetronic single point fuel injection (SPi)
system. Whilst the higher performance
1372 cc Turbo ie engine is fitted with a Bosch
L3.1 (L3.2 from 1992) Jetronic multi-point
injection (MPi) system and turbocharger with
intercooler and oil cooling. The L3.2 system
models are fitted with catalytic converters.
Maintenanceª
10At the intervals specified in Section 3 or
“Routine maintenance” at the beginning of
this Manual, carry out the following tasks.
11Check the engine oil level as follows. With
the vehicle parked on level ground, and with
the engine having been stopped for a few
minutes, withdraw the oil level dipstick, wipe it
on a clean rag, and re-insert it fully. Withdraw
the dipstick again and read off the oil level
relative to the MAX and MIN marks. The oil
level should be between the marks. If the level
is at or below the MIN mark, top up through
the filler on the camshaft cover without delay
(photo). The quantity of oil required to raise
the level from MIN to MAX on the dipstick is
approximately 1.0 litre (1.8 pints). Do not
overfill.
12Renew the engine oil and filter as
described in Section 2 of Chapter 1 (photos).
13Check and if necessary adjust the valve
clearances as described in Part B of this
Section.
14Inspect the engine for signs of oil, coolant
or fuel leaks and rectify as necessary.
15Inspect the crankcase ventilation hose for
blockage or damage. Clean or renew as
necessary.
16Check the condition and tension of thetiming belt as described in Part B of this
Section.
17Renew the timing belt as described in
Part B of this Section.
PART B:
OPERATIONS POSSlBLE
WITH ENGINE IN CAR
Valve clearances -
checking and adjustment#
1It is important to ensure that the valve
clearances are set correctly, as incorrect
clearances will result in incorrect valve timing
thus affecting engine performance.
2The clearances must be checked and
adjusted with the engine cold.
3On the ie engine, refer to Section 9 in this
Chapter for details and remove the air cleaner
unit.
4On the ie engine disconnect the crankcase
ventilation hose from the injector unit and
position the hose out of the way.
5On Turbo ie engines, loosen off the clips
and remove the air hose to the inlet manifold
(above the camshaft cover).
6On Turbo ie engines, disconnect the
accelerator cable from the throttle housing
and the support bracket on the camshaft
cover.
7Unscrew the securing nuts and washers
and remove the camshaft cover, noting that
on later models two of the nuts also secure
the hose clip assembly. Recover the gasket.
8Numbering from the front (timing belt) end
of the engine, the exhaust valves are 1, 4, 5
and 8, and the inlet valves are 2, 3, 6 and 7.
Supplement: Revisions and information on later models 13•37
7A.12B Engine oil filter removal using a
strap wrench - 1372 cc engine7A.12A Engine sump drain plug - 1372 cc
engine7A.11 Topping up the engine oil level -
1372 cc engine
Fig. 13.15 Engine oil level dipstick location
and level markings on the 1372 cc ie and
Turbo ie engines (Sec 7A)
13

9Turn the engine clockwise using a suitable
socket on the crankshaft pulley bolt, until the
exhaust valve of No 1 cylinder (valve No 1) is
fully closed; ie the cam lobe is pointing
directly upwards. Alternatively, the engine can
be turned by jacking up one front corner of
the vehicle and supporting it securely on an
axle stand (apply the handbrake and chock
the diagonally-opposite rear wheel before
jacking), engaging top gear and turning the
raised roadwheel in the forward direction of
travel. In both cases, it will be easier to turn
the engine if the spark plugs are removed, but
if this is done, take care not to allow dirt or
other foreign matter to enter the spark plug
holes.
10Insert a feeler gauge of the correct
thickness between the cam follower shim and
the heel of the No 1 cam lobe (photo). If
necessary, increase or reduce the thickness
of the feeler gauge until it is a firm sliding fit.
Record the thickness of the feeler gauge,
which will represent the valve clearance for
this particular valve.
11Turn the crankshaft, and repeat the
procedure for the remaining valves, recording
their respective clearances. Note that the
clearance for inlet and exhaust valves differs.
12If a clearance is incorrect, the relevant
cam follower shim must be removed, and a
thicker or thinner shim must be fitted to
achieve the correct clearance. To remove a
shim proceed as follows.
13Turn the crankshaft until the relevant cam
lobe is pointing directly upwards.
14The cam follower must now be depressed
in order to extract the shim. FIAT special tool
No 1860642000 is available for this purpose,
but alternatively a suitable tool can be
improvised (photo). The tool should locate on
the rim of the cam follower, leaving enough
room for the shim to be prised out by means
of the cut-outs provided in the cam follower
rim. Depress the cam follower by turning the
crankshaft as described previously until the
relevant cam lobe is pointing directly
downwards, then fit the tool between the
camshaft and the edge of the cam follower to
retain the cam follower in the depressed
position.
15Ensure that the tool is securely located, asthere is a risk of personal injury if the tool is
dislodged whilst the cam follower is
depressed, then turn the crankshaft until the
relevant cam lobe is pointing directly
upwards, leaving sufficient room to extract
the shim (photo). A pair of angle-nosed pliers
will greatly ease removal of the shim.
16Once the shim has been extracted,
establish its thickness. The thickness in mm
should be stamped into the face of the shim,
although it is possible for wear to obliterate
the number, in which case the use of a metric
micrometer is the only way to accurately
establish the thickness.
17Refer to the clearance recorded for the
valve concerned. If the clearance recorded
was larger than that specified, a thicker shim
must be fitted, and if the clearance recorded
was smaller than that specified, a thinner shim
must be fitted. The required thickness of shim
can be
calculated as follows.
Sample calculation - clearance too large:
Desired clearance (A) 0.40 mm
Measured clearance (B) 0.45 mm
Difference (B - A) + 0.05 mm
Original shim thickness 3.40 mm
Required shim thickness 3.40 + 0.05 =
3.45 mm
Sample calculation - clearance too small:
Desired clearance (A) 0.50 mm
Measured clearance (B) 0.35 mm
Difference (B - A) 0.15 mm
Original shim thickness 4.55 mm
Required shim thickness 4.55 - 0.15 =
4.40 mm
18Shims are available in thicknesses from
3.20 to 4.70 mm, in steps of 0.05 mm. Note
that if several shims have to be changed, they
can often be interchanged, thus avoiding the
need by buy more new shims than are
necessary.
19The shims should be fitted to the cam
followers with the stamped thickness marking
against the face of the cam follower.
20After fitting a shim, rotate the crankshaft
as described previously until the relevant cam
lobe is pointing directly downwards (resting
on the shim), then carefully remove the tool
used to retain the follower in the depressed
position.21Re-check each relevant valve clearance
after fitting the shim.
22On completion, where applicable, lower
the vehicle to the ground.
23Refit the camshaft cover, using a new
gasket.
24On the ie engine, reconnect the hoses and
refit the air cleaner unit.
25On the Turbo ie engine, reconnect the air
hose and the accelerator cable.
Timing belt tensioner
and sprockets -
removal and refitting
#
Note: The timing belt must be renewed after
removal: never refit a used drivebelt. When
fitting the new timing belt it will need to be
correctly tensioned and to achieve this the
manufacturers specify the use of special tools
1860745200 (18760745300 on Turbo model)
and 1860745100. If these tools are not readily
available, an approximate setting can be
made, but in this instance it is strongly
recommended that the car be taken to a FIAT
dealer at the earliest opportunity to have the
belt tension checked and correctly set using
the recommended tools.
26Loosen off the front right-hand side wheel
bolts, then raise and support the car at the
front end on axle stands. Remove the front
right-hand roadwheel.
27Remove the underwing shield from the
right-hand wheel arch to allow access to the
lower timing cover and alternator fixings (photo).
13•38 Supplement: Revisions and information on later models
7B.27 Underwing shield (A) showing
central compression pin (B) and retaining
clip (C). Drive pin through clip to remove
7B.15 Removing a shim from a cam
follower7B.14 Special tool for retaining cam
follower in depressed position7B.10 Measuring a valve clearance
(No 2 valve shown)

28Loosen off the retaining clips and detach
the air intake pipe from the air filter.
29Slide back the inspection cover from the
upper end of the timing cover (photo).
30Turn the engine over by hand to bring the
TDC timing marks of the flywheel-
to-bellhousing and the camshaft sprocket
-to-rear cover projection into alignment. The
crankshaft pulley also has a TDC timing mark
and this should be positioned as shown
(photos).
31Loosen off the retaining and adjustment
strap fixings, then pivot the alternator towards
the engine.
32Unscrew the upper retaining bolts
securing the timing cover.
33Loosen off the nut securing the alternator
and its drivebelt relay, then detach and
remove the alternator drivebelt.
34Unscrew and remove the crankshaft
pulley nut. Where the engine is in the car,
prevent the crankshaft from turning by
engaging top gear and having an assistant
apply the brake pedal hard. Unscrew and
remove the flywheel housing lower cover bolts
and remove the cover. The flywheel ring gear
can now be jammed with a suitable lever or
implement to prevent the crankshaft from
rotating. It should be noted that the pulley nut
is tightened to a considerable torque and a
strong socket, together with an L-bar and
extension tube, will therefore be required to
loosen and remove it (photo). Take care not todamage the gearbox/flywheel housing by
jamming the flywheel at a weak point.
35Withdraw the crankshaft pulley (photo).
36Unscrew and remove the lower retaining
bolts and remove the timing cover upwards
from the vehicle.
37Check that the previously mentioned
timing marks are still in alignment. Loosen off
the timing belt tensioner nut, then with the
tension released, withdraw the timing belt
from the sprockets.
38To remove the drivebelt tensioner, undo
the securing nut and withdraw the tensioner
pulley unit noting that it is in three sections
(photos).
39If desired, the sprockets and the rear
timing belt cover can be removed as follows,
otherwise proceed to paragraph 49.40To remove the camshaft sprocket, a
suitable tool must be used to hold the
camshaft stationary as the sprocket bolt is
loosened. A suitable tool can be improvised
as shown in photo 7B.48 using two pieces of
steel bar joined together by a pivot bolt, with
suitable bolts through the ends of the steel
bars to engage with the holes in the sprocket.
41Unscrew the sprocket bolt, then recover
the plain washer, and the thrust washer which
is bonded into a plastic sleeve (photo).
42The sprocket can now be withdrawn from
the end of the camshaft. If the sprocket is
tight, carefully lever it from the camshaft using
two screwdrivers, but take care not to
damage the rear timing belt cover.
43The crankshaft sprocket can be removed
by simply pulling it from the end of the
Supplement: Revisions and information on later models 13•39
7B.30B Crankshaft pulley and timing cover
timing marks7B.30A Camshaft sprocket timing notch
aligned with timing (TDC) pointer in timing
case7B.29 Slide back inspection cover in the
timing case
7B.41 Removing the crankshaft sprocket
bolt, plain washer and thrust washer7B.38B The three sections of the timing
belt tensioner
7B.35 Crankshaft pulley removal7B.34 Crankshaft pulley nut removal
7B.38A Timing belt tensioner removal
13

thumb and forefinger at the centre of the run
between the auxiliary shaft sprocket and the
camshaft sprocket. Using this method it
should just be possible to twist the belt
through 90º using moderate pressure.
55To adjust the tension, loosen off the
tensioner pulley nut then insert two rods (or
screwdrivers) into position in the pulley holes
and position a lever between them.
56Gently lever the tensioner pulley in the
required direction to set the tension as
described, then initially tighten the pulley nut
to lock the tensioner in the required position.
57Remove the tools from the tensioner,
recheck the tension and then tighten the
tensioner pulley nut securely.
58Rotate the crankshaft clockwise through
two complete turns using a socket or spanner
on the crankshaft pulley nut, then recheck the
belt tension. To avoid the possibility of
unscrewing the pulley nut, remove the spark
plugs to enable the engine to be turned over
easier.
59If further adjustment is required, repeat
the previously mentioned procedures. If in
doubt, err on the slightly tight side when
adjusting the tension. If the belt is set too
loose, it may jump off the sprockets resulting
in serious damage.
60Remove the crankshaft pulley retaining
nut, fit the timing belt cover, then refit and
tighten the pulley nut to the specified torque
setting.
61Refit the remaining components in the
reverse order of removal. Tighten the retaining
nuts/bolts to the specified torque settings
where given. Adjust the tension of the
alternator drivebelt as described in Section 8.
Adjustment using FIAT special
tools
62Assemble the special tools and fit them to
the belt tensioner pulley as shown in
Fig. 13.16. When fitted, the tool rod must be
as vertical as possible and it is important to
note that no sliding weights must be attached
to tool No. 1860745100.
63Slacken the tensioner pulley nut, if not
already done. Rotate the crankshaft clockwise
through two complete turns using a socket or
spanner on the crankshaft pulley nut. The
special tool rod may move from the vertical asthe engine is turned over, in which case the
joint will need to be re-adjusted to return the
rod to the vertical and the operation repeated.
64With the two revolutions of the crankshaft
completed, tighten the belt tensioner pulley
nut securely and remove the special tools.
65Remove the crankshaft pulley retaining
nut, fit the timing belt cover, then refit and
tighten the pulley nut to its specified torque
setting.
66Refit the remaining components in the
reverse order of removal. Tighten the retaining
nuts/bolts to the specified torque settings
where given. Adjust the tension of the
alternator drivebelt as described in Sec-
tion 8.
Camshaft front oil seal -
renewal#
67The camshaft front oil seal may be
renewed with the engine in the vehicle, and
the camshaft in situ, as follows.
68Remove the timing belt and the camshaft
sprocket as described previously in this
Section.
69Punch or drill a small hole in the centre of
the exposed oil seal. Screw in a self-tapping
screw, and pull on the screw with pliers to
extract the seal.
70Clean the oil seal seat with a wooden or
plastic scraper.
71Lubricate the lips of the new seal with
clean engine oil, and drive it into position until
it is flush with the housing, using a suitable
socket or tube. Take care not to damage the
seal lips during fitting. Note that the seal lips
should face inwards.
72Refit the camshaft sprocket and thetiming belt as described previously in this
Section.
Camshaft, housing and
followers -
removal and refitting
#
Note: The engine must be cold when
removing the camshaft housing. Do not
remove the camshaft housing from a hot
engine. New camshaft housing and camshaft
cover gaskets must be used on refitting.
73If the engine is still in the vehicle,
disconnect the battery negative lead.
74Refer to paragraphs 3 to 7 in this part of
this Section for details and remove the
camshaft cover.
75Remove the camshaft sprocket and timing
belt as described previously in this Section.
76Remove the three securing nuts and the
single securing bolt, and withdraw the upper
section of the rear timing belt cover.
77Unscrew the camshaft housing securing
bolts. There are seven bolts which are
accessible from outside the camshaft
housing, and five shorter bolts which are
accessible from inside the housing (these
bolts are normally covered by the camshaft
cover). Note that each bolt is fitted with two
washers (photo).
78Carefully lift the camshaft housing from
the cylinder head. Be prepared for the cam
followers to drop from their bores in the
camshaft housing as the camshaft housing is
lifted, and ensure that the cam followers are
identified for position so that they can be
refitted in their original positions (this can be
achieved by placing each cam follower over
its relevant valve in the cylinder head).
Supplement: Revisions and information on later models 13•41
Fig. 13.16 FIAT special tool No. 1860745100 (A) for timing belt adjustment shown fitted to
the tensioner pulley - 1372 cc ie and Turbo ie engines (Sec 7B)
Use with adapter No. 1860745200 on 1372 cc ie engines and No. 1860745300 on 1372 cc
Turbo ie engines
7B.77 Removing one of the camshaft
housing shorter securing bolts
13

98Commence reassembly by liberally oiling
the bearings in the housing, and the oil seal lip.
99Carefully insert the camshaft into the
housing from the blanking plate/distributor
end, taking care to avoid damage to the
bearings.
100Refit the blanking plate using a new
gasket.
101Refit the camshaft housing as described
previously in this Section.
Cylinder head
(1372 cc ie engine) -
removal and refitting
#
Note: The following instructions describe
cylinder head removal and refitting leaving the
camshaft, manifolds and associated items in situ
In the head. If required, these items can be
removed separately. When removing the
cylinder head the engine must be cold - do not
remove the head from a hot engine. A new
cylinder head gasket and any associated gaskets
must be used during reassembly. FIAT specify
that the main cylinder head bolts should be
renewed after they have been used (ie tightened)
four times. If in any doubt as to the number of
times that they have been used renew them as a
precaution against possible failure.
Warning: Refer to the beginning
of Section 9 before starting any
work.
102Depressurise the fuel supply system as
described in Section 9 of this Chapter.
103Disconnect the battery negative lead.
104Drain the engine coolant as described in
Section 8.
105Remove the air cleaner unit as described
in Section 9.
106Remove the timing belt as described
previously in this Section.107Disconnect the crankcase ventilation
hose from the cylinder head and the SPi
injector unit.
108Disconnect the accelerator cable at the
engine end.
109Detach the engine idle speed check
actuator lead, the inlet manifold vacuum
sensor lead, the coolant temperature sensor
lead, the injector supply lead, the throttle
position switch lead and the distributor cap
(with HT leads). Position them out of the way.
110Disconnect the brake servo hose from
the manifold.
111Disconnect the coolant hoses from the
thermostat and the inlet manifold.
112Slowly release the fuel supply and return
hose retaining clips and detach the hoses
from the injector unit housing and
connections. Catch any fuel spillage in a clean
cloth and plug the hoses to prevent the
ingress of dirt and further fuel loss.
113Unbolt and detach the exhaust downpipe
from the manifold.
114Loosen off the cylinder head retaining
bolts in a progressive manner, reversing the
sequence shown in Fig. 13.17. When all of the
bolts are loosened off, extract them and
collect the washers.
115Check that all fittings and associated
attachments are clear of the cylinder head,
then carefully lift the head from the cylinder
block. If necessary tap the head lightly with a
soft-faced mallet to free it from the block, but
do not lever it free between the joint faces.
Note that the cylinder head is located on
dowels.116Recover the old cylinder head gasket and
discard it.
117Clean the cylinder head and block mating
surfaces by careful scraping. Take care not to
damage the cylinder head - it is manufactured in
light alloy and is easily scored. Cover the coolant
passages and other openings to prevent dirt and
carbon from falling into them. Mop out all the oil
from the cylinder head bolt holes - if oil is left in
them, hydraulic pressure, caused when the bolts
are refitted, could cause the block to crack.
118If required the cylinder head can be
dismantled and overhauled as described in
paragraphs 129 to 131 of this Section.
119The new gasket must be removed from
its protective packing just before it is fitted.
Do not allow any oil or grease to come into
contact with the gasket. Commence refitting
the cylinder head by locating the new gasket
on the cylinder block so that the word “ALTO”
is facing up (photo).
120With the mating faces scrupulously
clean, refit the cylinder head into position and
engage it over the dowels. Refer to the note at
the beginning of this part of the Section, then
refit the ten main cylinder head bolts and
washers. Screw each bolt in as far as possible
by hand to start with. Do not fit the smaller
(M8 x 1.25) bolts at this stage (photos).
121The bolts must now be tightened in stages
and in the sequence shown in Fig. 13.17. Refer
to the specified torque wrench settings and
tighten all bolts to the Stage 1 torque, then
using a suitable angle gauge, tighten them to
the second stage, then the third stage (photos).
122With the main cylinder head bolts fully
Supplement: Revisions and information on later models 13•43
7B.120B . . . and engage the positioning
dowels in their holes7B.120A Lower the cylinder head onto the
block . . .7B.119 Locating a new cylinder head
gasket on the cylinder block (engine
shown on dismantling stand)
7B.121A Tighten main cylinder head bolts
to specified torque . . .Fig. 13.17 Cylinder head bolt tightening
sequence on the 1372 cc ie and Turbo ie
engines (Sec 7B)
13
7B.121B . . . and then through the specified
angle

tightened, refit the five smaller (M8 x 1.25)
bolts adjacent to the line of the spark plug
holes and tighten them to their specified
torque wrench setting (photo).
123Reconnect the associated fittings to the
cylinder head in the reverse order of removal.
Ensure that the mating faces of the exhaust
manifold-to-downpipe are clean and fit a new
gasket when reconnecting.
124Ensure that all wiring connections are
cleanly and securely made.
125Top up the engine oil and coolant levels
as required on completion.
Cylinder head
(1372 cc Turbo ie engine)
- removal and refitting
#
126Proceed as described in paragraphs 102
to 125 above for the non-Turbo model, but
note the following differences.127The cylinder head cannot be removed
and refitted with the manifolds and
turbocharger fitted. It is therefore first
necessary to detach and remove the inlet
manifold, then the turbocharger and the
exhaust manifold as described in Section 9.
128The ignition distributor is mounted on the
side of the engine, not the rear end of the
cylinder head as on the “ie” engine. It is
therefore only necessary to disconnect the HT
leads from the spark plugs.
Cylinder head - inspection
and renovation¢
Note: Refer to a dealer for advice before
attempting to carry out valve grinding or seat
recutting operations. These operations may
not be possible for the DIY mechanic due to
the fitment of hardened valve seats for use
with unleaded petrol.129Use a straight-edge to check the cylinder
head gasket surface for distortion. If it
exceeds the specified tolerance, it must be
resurfaced by a FIAT dealer or automotive
engineer.
130Refer to Section 39 in Chapter 1 for the
general details on dismantling and renovating
operations on the cylinder head but note that
there is a spring seat and a flat washer fitted
between the cylinder head and the valve
springs (photos).
Crankshaft front oil seal -
removal and renewal#
131Remove the timing belt as described
earlier in this Section. Note that as mentioned
previously, the timing belt will need to be
renewed during reassembly.
132Referring to Fig. 13.18, loosen off the bolt
indicated from the timing belt rear cover.
13•44 Supplement: Revisions and information on later models
7B.130H . . . the outer spring . . .7B.130G . . . the inner spring . . .7B130F . . . locate the spring seat . . .
7B.130E Refit the flat washer . . .7B.130D . . . and drive it into position7B.130C . . . locate stem oil seal . . .
7B.130B Valve assembly - 1372 cc engine;
insert valve into guide . . .7B.130A Inlet (A) and exhaust (B) valves
and associate components - 1372 cc
engine7B.122 Tighten the smaller cylinder head
bolts to their specified torque setting

new oil seal, ensuring that it is correctly
orientated, and drive it squarely into position.
149Refit all disturbed components.
Flywheel - removal,
inspection and refitting#
150If not already done, remove the clutch as
described in Chapter 5.
151Prevent the flywheel from turning by
jamming the ring gear teeth, or by bolting a
strap between the flywheel and the cylinder
block.
152Make alignment marks on the flywheel
and the end of the crankshaft, so that the
flywheel can be refitted in its original position.
153Unscrew the securing bolts and remove
the washer plate, then withdraw the flywheel.
Do not drop it, it is very heavy.
154With the flywheel removed, the ring gear
can be examined for wear and damage.
155If the ring gear is badly worn or has
missing teeth it should be renewed. The old
ring gear can be removed from the flywheel by
cutting a notch between two teeth with a
hacksaw and then splitting it with a cold
chisel. Wear eye protection when doing this.
156Fitting of a new ring gear requires heating
the ring to a temperature of 80ºC (176ºF). Do
not overheat, or the hard-wearing properties
will be lost. The gear has a chamfered inner
edge which should fit against the shoulder on
the flywheel. When hot enough, place the gear
in position quickly, tapping it home ifnecessary, and let it cool naturally without
quenching in any way.
157Ensure that the mating faces are clean,
then locate the flywheel on the rear of the
crankshaft, aligning the previously made
marks on the flywheel and crankshaft.
158Fit the washer plate, and insert the
securing bolts, then prevent the flywheel from
turning as described in paragraph 151 whilst
the bolts are tightened progressively to the
specified torque setting in a diagonal
sequence (photos).
159If applicable, refit the clutch as described
in Chapter 5.
Sump -
removal and refittingÁ
160Drain the engine oil from the sump as
described in Chapter 1.
161Disconnect the lead from the engine oil
level sensor in the sump.
162Unscrew and remove the bolts retaining the
gear linkage mounting bracket (where applicable)
and the clutch housing lower cover bolts.
Remove the cover from the clutch housing.
163Unscrew and remove the sump retaining
bolts and nuts and lower the sump from the
crankcase. Recover the gasket.
164Clean all traces of old gasket from the
sump, crankcase and both oil seal housing
mating surfaces.
165Commence reassembly by applying
sealing compound (FIAT No. 5882442 orequivalent) to the joints between the
crankshaft front and rear oil seal housings and
the mating face of the crankcase (photo).
166Locate the new gasket in position on the
crankcase then fit the sump. As it is fitted it
will need to be twisted to avoid fouling the oil
pump unit. Refit the retaining bolts and nuts
and tighten them to the specified torque
(photos).
167Check that the sump drain plug is refitted
and fully tightened. If the engine is in the car,
top up the engine oil level.
Oil pump - removal,
checking and refittingª
168Drain the engine oil and remove the
sump as described in the previous
sub-Section.
169Unscrew the retaining bolts then
withdraw the oil pump and intake pipe/filter
from its location within the crankcase.
Remove the gasket.
170If oil pump wear is suspected, first check
the cost and availability of new parts and the
cost of a new pump. Then examine the pump
as described below and decide whether
renewal or repair is the best course of action.
171Unscrew the three securing bolts and
remove the oil pump cover (photo). Note that
as the cover is removed, the oil pressure relief
valve components will be released.
172Recover the oil pressure relief valve,
spring and spring seat.
13•46 Supplement: Revisions and information on later models
7B.166C . . . and insert the retaining bolts7B.166B . . . refit the sump . . .7B.166A Locate the new gasket . . .
7B.165 Apply sealant to the front oil seal
housing/cylinder block joint7B.158B . . . tighten the bolts to the
specified torque7B.158A Locate the flywheel, washer plate
and bolts . . .