2B»1
Chapter 2 Part B:
DOHC (16-valve) petrol
engine in-car repair procedures
Contents
Auxiliary drlvebelts - removal and refitting See Chapter 1A Camshaft oil seal - renewal 6 Camshafts and cam followers - removal, inspection and refitting .. 9 Crankshaft oil seals • renewal 7 Cylinder compression test 3 Cylinder head - dismantling and overhaul See Chapter 2D Cylinder head • removal and refitting 10 Cylinder head extension • removal and refitting 8 Engine assembly/Valve timing holes - general information and usage 2
Engine mountings - inspection and renewal 12 Engine oil and filter - renewal See Chapter 1A Engine oil level - check See Weekly checks Flywheel - removal, Inspection and refitting 11 General Information 1 Oil pump and pick-up tube - removal, inspection and refitting 14 Sump - removal and refitting 13 Timing belt and covers - removal and refitting 4 Timing belt tensioner and sprockets • removal and refitting 5
Degrees of difficulty
Easy,
sitable
for
J; Fairly
easy,
suitable Fairtydifflcutt, ^
Difficult,
aitabtefcr Very
difficult,
^ nwice
wim
(ttls for beginner with £
suitable
for competent KYmechanic ^ experienced DIY > suitable
for
expert DIY« experience
some
experience £
suitable
for competent KYmechanic ^ mechanic > or professional ^
Specifications
General Engine code* 176.09.000 •Note: See Vehicle Identification for the location of code marking on the engine. Bore 70.8 mm Stroke 78.86 mm Capacity 1242 cc Compression ratio 10.2:1 Firing order 1-3-4-2 No
1
cylinder location Timing belt end of engine Timing belt tension See text
Camshaft Orlve Toothed belt
No
of bearings 3 Camshaft bearing journal diameters: Ho
1
bearing 35.000 to 35.015 mm
Mo
2 bearing 48.000 to 48.015 mm No 3 bearing 49.000 to 49.015 mm Camshaft bearing Journal running clearance 0.030 to 0.070 mm Camshaft endfloat 0.15 to 0.34 mm
Cylinder head extension Camshaft bearing diamelers: No
1
bearing 35.045 to 35.070 mm No 2 bearing 48,045 to 48.070 mm No 3 bearing 49.045 to 49.070 mm
Cam
follower (tappet) type Hydraulic
Cam
follower (tappet) diameter 28.353 to 28.370 mm
Cam
follower (tappet) bore diameter in cylinder head extension 28.400 to 28.421 mm
Cam
follower (tappet) running clearance 0.046 to
0.051
mm
2A*10 SOHC (8-valve) petrol engine in-car repair procedures
Lubrication system Oil pump type By-rotor driven from front of crankshaft Outer rotor-io-houslng clearance 0.100 to 0.210 mm Axial clearance 0.025 to 0.070 mm
Torque wrench settings Nm itrf ft Camshaft driven gears 120 89 Camshaft sprocket 120 89 Crankshaft sprocket centre bolt: Stage
1
20 15 Stage 2 Angle-tighten a further 90® Cylinder head: Stage
1
30 22 Stage 2 Angle-tighten a further 90" Stage 3 Angle-tighten a further 90° Cylinder head extension to cylinder head 15 11 Engine mounting bolt: M10
x
1.25 59 44 M8 25 18 Engine mounting nut (MlOx 1.25) 60 44 Flywheel 44 32 Timing belt tensioner 25 18 Sump 10 7
1 General information
Using this Chapter Chapter 2 is divided into four Parts; A, B. C and O. Repair operations that can be carried out with the engine hi the vehicle are described in Part A. SOHC (8-valve) petrol engines. Part B, DOHC (16-valve) petrol engines and Pari C, dlesei engines. Part D covers the removal of the engine/transmission as a unit, and describes the engine dismantling and overhaul procedures. In Parts A, B and C, the assumption Is made that the engine is Installed In the vehicle, with all ancillaries connected. If the engine has been removed for overhaul, the preliminary dismantling information which precedes each operation may be ignored.
Engine description Throughout this Chapter, engines are identified by their capacities. A listing of all engines covered, together with their code letters, Is given in the Specifications. The engine covered in this Part of Chapter 2 is a water-cooled, double overhead camshaft, in-line four-cylinder unit, with cast iron cylinder block and aluminium-alloy cylinder head. The unit is mounted transversely at the front of the vehicle, with the transmission bolted to the left-hand side of the engine. The cylinder head houses the eight inlet and eight exhaust valves, which are closed by single coil springs, and which run in guides pressed Into the cylinder head. The two camshafts are housed in 8 cylinder head extension which is bolted to the top of the cylinder head. The exhaust camshaft is driven by a toothed timing belt and In turn drives the inlet camshaft via a pair of gears located at the left-hand end of the cylinder head extension.
The camshafts actuate the valves directly via self-adjusting hydraulic cam followers mounted in the cylinder head extension. The crankshaft is supported by five main bearings, and endfioat is controlled by a thrust bearing fitted to (he upper section of the centre main bearing. Engine coolanl is circulated by a pump, driven by the timing belt. For details of the cooling system, refer to Chapter 3. Lubricant is circulated under pressure by a pump, driven from the front of the crankshaft. Oil is drawn from Ihe sump through a strainer, and then forced through an externally-mounted, replaceable screw-on filter. From there, It is distributed to the cylinder head and cylinder head extension, where it lubricates the camshaft journals and cam followers, and also to the crankcase, where it lubricates the main bearings, connecting rod big and small-ends. gudgeon pins and cylinder bores. Oil Jets are fitted to the base of each cylinder bore - these spray oil onto the underside of the pistons, to improve cooling.
Repair operations possible with the engine in the car The following work can be carried out with the engine in the car: a) Auxiliary drivebett - removal and refitting (refer to Chapter 1A) b) Oil pump and pick-up tube assembly -removal, Inspection and refitting c) Timing belt and covers • removal and refitting d) Timing belt tensioner and sprockets -removal and refitting e) Cylinder head - removal and refitting' f) Cylinder hoad extension - removal and refitting g) Camshaft and cam followers - removal and refitting h) Camshaft oil seal - renewal i) Crankshaft oil seals • renewal
f) Flywheel - removal, inspection and
refitting
k) Engine mountings - Inspection and
renews'
f) Sump • removal and refitting 'Cylinder head dismantling procedures are detailed In Chapter 2D. Note 1: It is possible to remove the
pistons
and connecting rods (after removing (to cylinder head and sump) without removing
tt*»
engine. However, this Is not recommended. Work of this nature is more easily and thoroughly completed with the engine on fix bench, as described in Chapter 20. Note
2x
Many of the procedures in this Ctopfer entail the use of numerous special tools. Whet possible, suitable alternatives are descnbei with details of their fabrication. Before starring any operations on the engine, read through
tto
entire procedure first to familiarise yourself
wft
the work involved, tools to be obtained mi new parts that may be necessary.
2 Engine assembly/ valve timing holes -genera! information
and
usage
Note: Do not attempt to rotate the angint whilst the camshafts are locked In position,
il
the engine is to be left in this state foratofi$ period of time. It Is a good idea to plect suitable warning notices inside the vehicle, and in the engine compartment. This wfl reduce the possibility of the engine being accidentally cranked on the starter motor, which is likely to cause damage with the locking tools In place. 1 To accurately set the valve timing for ell operations requiring removal and refitting of
the
timing belt, liming holes are drilled in ihe camshafts and cylinder head extension. Ihe holes are used In conjunction with camshaft locking tools and crankshaft positioning
rods w
lock the camshafts when all the pistons me positioned at the mid-point of their stroke. Ths
2B*4 DOHC (16-valve) petrol engine in-car repair procedures
4.8 Undo three bolts and romove tho crankshaft pulley from the sprocket
Crankshaft setting toot fabrication 7 To make Ihe crankshafl setting tools, four old spark plugs will be required, together with four lengths of dowel rod. The length of each dowel rod is not critical, bul It must be long enough to protrude about 100 mm above the top of the cylinder head extension when resting on top of a piston located half way down its bore. What is critical, however, is that all four do wo I rods must be exactly the same length. 8 Break off the ceramic upper section of each plug and remove the centre electrode and earth tip. The easiest way to do this is to mount each spark plug in a vice (attar removing the ceramic uppor plug section) and drill a hole down through ihe centre of the plug. The diameter of Ihe drill bit should be the same as Ihe diameter of Ihe dowol rod to be used. When finished you should have four spark plug bodies and four equal length dowel rods which will slide through the centre of the spark plugs.
3 Cylinder compression test
1 When engine performance is down, or it misfiring occurs which cannot be attnbuted to the Ignition or fuel systems, a compression test can provide diagnostic clues as to the engine's condition. If the lest is performed regularly, it can give warning of trouble bofore any other symptoms become apparent.
4.10 Undo the upper timing cover upper retaining bolt, and the rear retaining boll
4.9 Undo the retaining bolt in the centre of the lower timing cover
2 The engine must be fully warmed-up to normal operxrtrfjg temperature, the battery must be fully charged, and all the spark plugs muse be removed (Chapter 1A>. The aid of an assistant wilt also be required. 3 Disable the ignition system by discon-necting the LT wiring plugs to the Ignition coils. 4 Fit a compression tester to the No t cylinder spark plug hole • the type of tester which screws into the plug thread is to be preferred. 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the h.ghest reading obtained 6 Repeat the test on the remaining cylinders, recording Ihe pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates Ihe existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on (he first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked head could also be tho cause). 6 If the pressure in any cylinder is very low, carry out the following test to isolate the cause. Introduce a teaspoonful of dean oil into that cylinder through its spark plug hole and repeal the lest. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a blown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between Ihem; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower than the others and the engine has a slightly rough idle, a worn camshaft lobe could be the cause. 12 On completion of the test, refit the spark plugs and reconnect the ignition LT wiring plug.
4 Timing belt and covers -removal and refitting §
General information 1 The luncUon of the timing belt Is to drive the camshafts and coolant pump. Should the bell slip or creak in service, the valve timing will be disturbed and piston-to-valve contact wiu occur, resulting in serious engine damage. 2 The timing belt should be renewed at the specified Intervals (see Chapter 1A), or earlier If It is contaminated with oil, or if it is at all noisy In operation (a scraping noise due to uneven wear}. 3 If the timing belt is being removed, it is
a
wise precaution to check the condition of the coolam pump at the same time (oheck for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fail. 4 Before carrying out this procedure, it will be necessary to obtain or fabricate suitable camshaft locking tools and piston positioning tools as described in Section 2. The procedures contained In this Section depict the use of the home-made alternative tools described in Section 2. which were fabricated In the Haynes workshop. If the manufacturers tools are being used instead, the procedures are virtually identical. Oo not attempt to remove the timing bell unless the special totfs or their alternatives are available.
Removal 5 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of Ihis manual). 6 Remove the auxiliary drivebelt(s) as described In Chapter 1A. 7 Remove the air cleaner, Inlet air duct and resonator as desenbed In Chapter 4B. 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Undo the retaining bolt In the centre of the lower liming cover (see illustration). 10 Undo tho uppor timing cover upper retaining bolt, and the rear retaining bolt located above the alternator (see illustration). 11 Release the crankshaft TDC sensor wiring from the clip on the upper timing cover, then withdraw the cover slightly and slide Ihe wiring plug and socket from the liming cover slot (see illustrations). 12 Release the TDC sensor wiring from the periphery ol the upper and fower timing covers and remove both covers (see Illustrations). 13 Free the accelerator inner cable from the throttle cam, remove the outer cable spring dip, then pull the outer cable out from its mounting bracket rubber grommet. 14 From the side of the throttle body, disconnect the wiring connectors from the
2B*7 DOHC (16-valve) petrol engine in-car repair procedures
35 Slacken the tensioner pulley retaining nut and reposition the tensioner to align the
mobile
indicator with the fixed reference mark
on the
pulley face (see illustration). Hold the
pdley in
this position and tighten the retaining
nut to the
specified torque. 36 Turn the crankshaft through a further two complete turns In the normal direction of rotation. Check that the timing is correct by alining Ihe piston positioning tools and
camshaft
locking tools as described previously. 37 When all is correct, remove the setting rri
locking
tools and refit the sealing plugs to 1ft© cylinder head extension, using new 0-
nr^s if
necessary. Tighten the plugs securely. 38 Refit the spark plugs as described in Chapter 1A. 39 Refit Ihe ECU and secure with Ihe mooning bolts. 40
Renew the
injector O-ring seals, smear them Kith
8 little
Vaseline then locate the injectors and tef rail onto the inlet manifold lower section.
Saute Ihe fuel rail
with the two retaining bolts. 41 Relit the inlet manifold upper section using new sealing O-rlngs If necessary and
sectre
with the two bolts. 42 Reconnect the wiring connectors for the tot injector harness and the intake air temp-erature/pressure sensor, then connect the fuel pressure regulator vacuum hose and tha
EVAP
purge valve hose. 43 Reconnect the wiring connectors for the ihrottls potentiometer, idle control stepper motor and coolant temperature sensor. Reconnect the brake servo vacuum hose. 44 Refit and adjust the accelerator cable as described in Chapter 4B. 46 Refit the upper and lower timing belt
covers
together with the TDC sensor wiring. 46 Refit the crankshaft pulley and tighten the
three
retaining bolts securely. 47 Refit the air cleaner. Inlet air duct and resonator as described in Chapter 4B. 48
Refit
tha auxiliary drivebelt(s) as described i/t Chapter 1A, then reconnect the battery
S Timing belt tensioner
and
sprockets -
removal
and refitting
Timing
belt tensioner
Removal I
Remove
the timing belt as described in
Section
4. 1 Completely unscrew the tensioner nut and Wiethe tensioner off the mounting stud-Inspection
3 Wipe
the tensioner clean but do not use Kfrents that may contaminate the bearings.
Spin
the tensioner pulley on its hub by hand.
Sfcfl
movement or excessive freeplay is an rcfceticn of severe wear: the tensioner is not 3 serviceable component, and should be nnewsd.
4.33 Holding the camshaft sprocket with the tool described previously while tightening the sprocket bolt Refitting 4 Slide the tensioner pulley over the mounting stud and fit the securing nut. 5 Refit the timing belt as described in Section 4. Camshaft sprocket Removal 6 Remove the timing belt as described in Section 4. 7 Unscrew the bolt and slide the sprocket from the end of the camshaft. Inspection 8 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, refer to Section 6 and renew it. 9 Check the sprocket teeth for damage. 10 Wipe clean the sprocket and camshaft mating surfaces. Refitting 11 Locate the sprocket on the end of the camshaft, then refit the retaining boll finger tight only at this stage. 12 Refit the timing belt as described in Section 4.
Crankshaft sprocket Removal 13 Remove the timing bell as described In Section 4. 14 Working beneath the engine, unbolt and remove the flywheel lower cover, then hold the flywheel stationary preferably using a tool which engages the flywheel starter ring
<
Alternatively have an assistant engage a wide-bladed screwdriver with the starter ring gear. 15 Unscrew the crankshaft sprocket retaining bolt and slide the sprocket off the end of the crankshaft. The sprocket may have an integral location key on its inner face, or a separate key which locates In a groove in the crankshaft nose may be fitted. Inspection 16 With the sprocket removed, examine the crankshaft oil seal for signs of leaking. If necessary, refer to Section 7 and renew it. 17 Check the sprocket teeth for damage. 18 Wipe clean the sprocket and crankshaft mating surfaces. Refitting 19 Slide the sprocket onto the crankshaft making sure
11
engages the integral key or separate key, then refit the bolt and washer and tighten the bolt to the specified torque while holding the crankshaft stationary using the method described in paragraph 14. 20 Refit the timing belt as described in Section 4.
6 Camshaft
oil
seal -renewal
1 Remove the timing belt and camshaft sprocket as described in Sections 4 and 5. 2 Punch or drill a small hole in the oil seal. Screw a self-tapping screw into the hole, and pull on the screws with pliers to extract the seal. 3 Clean the seal housing, and polish off any burrs or raised edges, which may have caused the seal to fall in the first place. 4 Lubricate the lips of the new seal with clean engine oil, and drive it into position until It seats on its locating shoulder. Use a suitable tubular drift, such as a socket, which bears only on the hard outer edge of the seal. Take care nof to damage the seal lips during fitting. Note that the Seal lips should face inwards. 5 Refit the camshaft sprocket and timing belt as described in Sections 5 and 4.
7 Crankshaft oil seats -renewal I
4.35 Position the tensioner so that the mobile Indicator (1) is aligned with the fixed reference mark (2)
Front (right-hand side) oil seal 1 The front oil seal is located in the oil pump on the front of the crankshaft. Remove the timing belt as described in Section 4 and the crankshaft sprocket as described in Section 5. 2 Using a hooked Instrument, remove the oil seal from the oil pump casing taking care not to damage the surface of the crankshaft. 3 Clean the seating in the housing and the surface of the crankshaft. To prevent damage to the new oil seal as it is being fitted, wrap some adhesive tape around the end of the crankshaft and lightly oil it.
2C«1
Chapter 2 PartC:
Diesel engine in-car repair procedures
Contents
Auxiliary drivebelts - removal and refitting See Chapter 1B Camshaft cover - removal and refitting 6 Camshaft oil seal - renewal 7 Camshaft - removal and refitting See Chapter 20 Crankshaft oil seats - renewal 8 Cylinder compression test « 3 Cylinder head - dismantling and overhaul See Chapter 20 Cylinder head - removal and refitting 9 Engine mountings - inspection and renewal 11 Engine oil and fitter - renewal See Chapter 18 Engine oil level check See Weekly checks
Degrees of difficulty
Flywheel * removal, inspection and refitting 10 General information 1 Location of TDC on No 1 cylinder 2 Oil cooler - removal and refitting 14 Oil pump and pick-up tube • removal, Inspection and refitting 13 Sump • removal and refitting 12 Timing belt and covers • removal and refitting 4 Timing belt tensioner and sprockets - removal, Inspection and refitting 5 Valve clearance check and adjustment See Chapter 1B
Easy,
suitable for novice
with Irttle
|| experience g^
FaMy
eesy,
suitable ^
forbeglnnerwilti
some experience ^
Falrtydfficult, ^ suitable
for
competent DIYmechanic ^
Difficult, suitable
for & experienced DIY mechanic ^
Very
difficult,
^ suitable
for
expert
DfY
jR or professional ^
Specifications
General Engine code:' 1698 cc non-turbo engine 176.B3.000 1698 cc turbo engine: Up to 1997 t76.A3.00aor176.A5.000 1997 onward 176.A3.000or176.B7.000 •Note: See Vehicle Identification for the location of the code marking on the engine. Bore 82.6 mm Stroke 79.2 mm Compression ratio: Non-turbo engine 20.5:1 Turbo engine 19:1 Firing order 1-3-4-2
No 1
cylinder location Timing belt end of engine Titling belt tension See text
Lubrication system Oi pump type By-rotor driven from front of crankshaft Outer rotor-to-houslng clearance 0.080 to 0.186 mm Axial clearance 0.025 to 0.056 mm
Torque wrench settings Nm ibf ft Camshaft cover 10 7 Camshaft sprocket 11B 87 Crankshaft sprocket centre bolt 190 140 Cylinder head: Stage 1 50 37 Stage 2 100 74 StageS Angle-tighten a furtfier 90" Stage 4 Angle-tighten a further 90° CySnder head front bolts 30 22 Flywheel 142 105
Fuel
injection pump sprocket 49 36 Inlet and exhaust manifolds 25 18 Sump 10 7 Timing belt tensioner and idler 44 32
2C*2 Diesel engine in-car repair procedures
1 General information
Using this Chapter Chapter 2 is divided Into four Parts; A. 8, C and 0. Repair operations that cart be carried out with the engine in the vehicle are described In Part A, SOHC (B-valve) petrol engines. Part B, DOHC (16-valve) petrol engines and Part C. diesel engines, Part D covers the removal of the engine/transmission as a unit, and describes the engine dismantling and overhaul procedures. In Parts A. 8 and C. the assumption Is made that the engine is installed in Ihe vehicle, with all anciliaries connected If the engine has been removed for overhaul, the preliminary dismantling information which precedes each operation may be ignored.
Engine description Both normally aspirated (non-turbo) and turbocharged diesel engines are fitted to the Punto range. The engines together with their codes are given in the Specifications at the start of lhis Chapter. The engines are water-cooled, single-overhead camshaft. In-line lour cylinder units with cast-iron cylinder blocks and aluminium-alloy cylinder heads. The engine is mounted transversely at the front of the vehicle, with the transmission bolted to the left-hand side of the engine. The cylinder head carries the camshaft which is driven by a toothed timing belt. It also houses the inlet and exhaust valves which are closed by single coll valve springs and run in valve guides pressed into the cylinder head. The valves are operated by cam followers fitted over each valve, and the clearances are adjusted by shims positioned between the followers and the camshaft lobes. The camshaft is supported by four bearings • the end bearings are machined in the cylinder head and the remaining bearings have caps bolted to the cylinder head. The cylinder head contains integral oiiways which supply and lubricate the camshaft and followers and it also Incorporates renewable swirl chambers. The crankshaft Is supported by five main bearings, and endfloat Is controlled by a thrust bearing fitted on the rear main bearing. All diesel engines are fitted with a brake servo vacuum pump dnven from the left-hBnd end of the camshaft. Engine coolant is circulated by a pump, driven by the auxiliary drivebeit. For details of the cooling system refer to Chapter 3. Lubricant is circulated under pressure by a pump, driven from the front of the crankshaft. Oil is drawn from the sump through a strainer, and then forced through an externally-mounted, replaceable screw-on filter. From there, it is distributed to the cylinder head.
where il lubncates the camshaft journals and followers, and also to the crankcase, where it lubricates the main bearings, connecting rod big- and small-ends, gudgeon pins and cylinder bores. Oil jets are fitted to the base of each cylinder bore - these spray oil onto the underside of the pistons, lo Improve cooling. An oil cooler is also fitted to reduce the temp-erature of oil before it re-enters the engine.
Repair operations possible with the engine in the car The following work can be carried out with the engine in the can a) Compression pressure - testing b) Auxiliary drivebeit - removal and refitting (refer to Chapter rej c) Valve clearances • checking and adjustment (refer to Chapter 1B) d) Camshaft cover - removal and refitting e) Tim/ng belt and covers • removal and refitting 0 Timing belt tensioner and sprockets -removal and refitting g) Cylinder head - removal and refitting' h) Camshaft and cam followers - removal end refitting' I) Camshaft oil seal - renewal j) Crankshaft oil seals - renewal k) Flywheel • removal, inspection and refitting I) Engine mountings - inspection and renewal m)Sump • removal and refitting n) Oil pump and pick-up tube assembly -removal, inspection and refitting 'Cylinder head dismantling procedures are detalfed In Chapter 2D, with details of camshaft and cam follower removal. Note: It ts possible to remove the pistons and connecting rods (after removing the cylinder nead and sump) without removing the engine. However, this is not recommended. Work of this nature is more easily and thoroughly completed with the engine on tho bench as described in Chapter 2D.
2 Location of
TDC
on ^ No
1
cylinder ||
General information 1 The camshaft and fuel Injection pump are driven by the crankshaft, by means of sprockets and a timing belt. All three sprockets rotate in phase with each other and this provides the correct valve and injection pump timing as the engine rotates. When the timing bell is removed during servicing or repair, it is possible for the camshaft, injection pump and crankshaft to rotate independently of each other and the correct timing Is then lost.
2 It
Location of TDC on cylinder No
1
6 Remove the air inlet ducting as described ft Chapter 4C, Section 2. 7 Remove the heater glow plugs with reference to Chapter 5C. Due to the high compression ratio of diesel engines this Is necessary to allow the engine to be turned by hand. 8 Unscrew the mounting bolts and move the coolant expansion tank to one side for access to the timing covers. Release the hose from the clips on Ihe camshaft cover. 9 Release the toggle clips and remove the upper timing cover (see illustration),
2.9 Removing the upper timing cover
Diesel engine in-car repair procedures
2C*11
10 firmly apply the handbrake, then jack up
Ihe
front of the car and support it securely on
arte stands
(see Jacking and vehicle support). Remove the right-hand front roadwheel. 11 Working under the wheelarch. remove the splash guard, than unbolt and remove the outer cover over the crankshaft pulley (see ilustratlon). 12 Remove the auxiliary drivebelt(s) as described in Chapter 18. 13 Unbolt and remove the lower timing cover from the cylinder block (see Illustration). Note that one of the bolts is located at the
Iron!
of the engine. 14 Unscrew the four socket-headed bolts
and
remove the pulley from the front of the crankshaft (see illustrations). Recover the {pacer plate. 15 Turn the engine in its normal direction of rotation (using a socket or spanner on the crankshaft sprocket centre bolt) until pressure
can be
felt at No 1 cylinder gtowplug hole. 16 Continue turning the engine until the TDC timing marks on the camshaft and fuel injection pump sprockets are aligned with the corresponding marks on the timing belt inner cover, and the crankshaft sprocket timing
mark
is aligned with the mark on the oil pump cover (see illustration). 17 Tne engine is now set at TDC tor No 1 e>llnder on compression.
114a Unscrew and remove the socket-headed bolts and spacer...
2.11 Removing the outer cover over the 2.13 Removing the lower timing cover crankshaft pulley
2.14b ... and remove the pulley from the 2.18 Sprocket timing mark positioning with No 1 cylinder et TDC front of the crankshaft
Diesel engine in-car repair procedures
2C*11
C«/ffor>: Where applicable observe the drnctbn of rotation markings on the belt. 12 Tension the timing belt by turning the eccentrically-mounted tensioner clockwise: two ities are provided in the side of the tensioner ftb for this purpose - a pair of sturdy right-ircfed circiip pliers can be used to do this or iftemaiively two bolts and a long screwdriver
may be
used. Fiat use a special tensioner tool
located in
the hotos - this consists of a calibrated rod
and
weight. The weight is positioned 60 mm tog the rod to provide the correct tension to the belt, then the tensioner nul is tightened. Tgttn tho tensioner nut to the specified torque
(see
illustrations) 13
If the
tensioner tool Is not available, test the wsicn by grasping the timing belt between the li^er and thumb midway between the camshaft and injection pump pulleys, and Using il through 90" (see paragraph S).
Caution: The above procedure serves only as a rough guide to setting the belt tension. The tension must be checked accurately by a Fiat dealer using the spec/a/ fens/oner tool, at the earliest opportunity. 14 Tum the engine two complete turns clockwise, check that all the timing marks are still aligned then recheck the timing belt tension. If necessary carry out the tensioning procedure again, 15 Refit the components disturbed for access, using the reverse of the removal procedure and bearing In mind the following points: a) Tighten all nuts and bolts to the specified torque, where given. b) Refit the auxiliary dnvebelt(s) as described in Chapter 18.
5 Timing belt tensioner ^ and sprockets - removal, ^ inspection and refitting ^
1 Follow the procedure for removing the timing belt In Section 4, however it is not necessary to completely remove the belt from the timing sprockets provided it is kept fully engaged with them. 2 Unscrew the nut and slide the tensioner off the mounting stud (see illustrations).
Inspection 3 Wipe the tensioner clean but do not use solvents that may contaminate the bearings. Spin the tensioner pulley on its hub by hand. Stiff movemeni or excessive freeplay Is an Indication of severe wean the tensioner is not a serviceable component, and should be renewed, Refitting 4 Slide the tensioner pulley over the mounting stud and screw on the nut. 5 Refer to Section 4 and refit the timing belt.
Timing belt idler pulley
Removal 6 Remove Ihe timing belt as described In Section 4. 7 Unscrew the mounting bolt and remove the idler pulley from the front of the cylinder block (see illustration). Inspection 8 Wipe the idler clean but do not use solvents that may contaminate the bearings. Spin the idler pulley on Its hub by hand. Stiff movement or excessive freeplay Is an Indication of severe wear; the Idler is not a serviceable component, and should be renewed. Refitting 9 Refit the idler to the front of the block and tighten the bolt to the specified torque (see illustration). 10 Refer to Section 4 and refit the liming belt.
Timing belt tensioner
Removal
5.9 Tightening the idler pulley mounting bolt