1999 FIAT PUNTO timing belt

2B*6 DOHC (16-valve) petrol engine in-car repair procedures
4.24a Scrow in the camshaft locking tools into the timing holes in the cylinder head extension
locking tools Into the timing holes in the cylinder head extension. To provide the necessary degree of timing accuracy, the machined end of the locking tools are a very close fit in the slots machined in the camshafts. To allow the tools to be screwed
4.26 Slip the timing belt off the sprockets
To make a camshaft sprocket holding tool, obtain two lengths of steel strip about 6 mm thick by 30 mm wide or simitar, one 600 mm long, the other
200
mm long (all dimensions approximate). Bolt the two strips together to form a forked end, leaving the bolt slack so that the shorter sfrfp can pivot freely. At the end of each 'prong' of the fork, secure a bolt with a nut and a locknut, to act as the fulcrums; these will engage with the cut-outs In the sprocket, and should profrude by about 30 mm
4.24b The tools engage in tho camshaft slots when fitted (shown removed for clarity)
fully into engagement, it may be necessary to move the crankshaft In one direction or another very slightiy until the tools are felt to engage fully (see illustrations). 25 Release tho nut on the timing belt tensioner to release the tension on the belt (see illustration) 26 II the timing belt is to be re-used, use white paml or chalk to mark the direction of rotation on the belt (if markings do not already exist), then slip the belt off the sprockets (see illustration). Note that the crankshaft must not be rotated whilst the belt is removed. 27 Check the timing belt carefully for any signs of uneven wear, splitting, or oil contamination. Pay particular attention to the roots ol the teeth. Renew it If there is the slightest doubt about its condition. If the engine is undergoing an overhaul, renew the belt as a matter of course, regardless of its apparent condition. The cost ol a new bett is nothing compared with the cosi of repairs, should the belt break in service. If signs of oil contamination are found, trace the source of the oil leak 8nd rectify it. Wash down the engme timing belt area and all related components, to remove all traces of oil,
Refitting 28 Before refilling, thoroughly clean the liming bell sprockets. Check that Ihe tensioner pulley rotates freely, without any sign of roughness. If necessary, renew Ihe tensioner pulley as described in Section 5,
4.31 Fit the new belt around the sprockots observing the direction markings
4.25 Release the nut on the timing belt tensioner (arrowed)
29 The camshaft sprocket retaining bolt mutt; now be slackened to allow the sprocket Ic move as the timing bell Is refitted una tensioned. To hold the sprocket stationary^ while the retaining bolt is loosened, make upi. tool os follows and engage
>t
with the holes ^ i the sprocket (see Tool Tip). With the sprocket. held, slacken the retaining bolt. 30 Check that the pi6tons are still correct positioned at ihe mid-point of their stroke are that the camshafts are locked with the lockup: tools. 31 Ensuring that the direction markings on the timing belt point in the normal direction
cf
engine rotation, engage the Umlng belt vr* Ihe crankshaft sprocket first, then placed around the coolant pump sprocket and tte: camshaft sprocket (see Illustration). Rnaii>; slip the belt around the tensioner pulley. 32 Insert the jaws of a pair of right-angleo clrclip pliers (or similar) into Ihe two holes on; Ihe front face of the tensioner pulley (sec Illustration). Rotate the pulley to tension Ihj; belt until the belt Is quite taut. Maintain thr effort applied to the tensioner pulley. JM* tighten the pulley retaining nut. 33 Tighten the camshaft sprocket retains; bolt to the specified torque while holding th?; camshaft stationary using the method described previously (see Illustration). 34 Remove the piston positioning tools arc camshaft locking tools and turn In*; crankshaft through two complete turns In the normal direction of rotation,
4.32 Using right-angled clrclip pliers, turn the tensioner pulley to fully tension the bell

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.

2B*8 DOHC (16-valve) petrol engine in-car repair procedures
8.3a Disconnect the LT wiring plugs from the two Ignition coils ... 4 Dip the new oil seal in oil then offer it up to the oil pump casing making sure that the sealing Hps are facing inwards. 5 Using a suitable tubular drift, drive the oil seal squarely into the casing. Remove the adhesive tape, 8 Reftl the crankshaft sprocket and timing belt wrth reference to Sections 5 and
Rear (left-hand side) oil seal Note: The following paragraphs describe renewal of the rear oil seal leaving the housing in position. Refer to Chapter 20 for details of removing ihe housing. 7 Remove the flywheel as described In Section 11. 8 Using a suitable hooked Instrument, remove the oil seal from the rear oil seal
L •
~ 1 8.8a Lift the cylinder head extension slightly and insert the tools {shown with cylinder head removed for clarity)...
8.3b ... then unscrew the mounting bolts end romove the ignition colls housing taking care not to damage the surface of the crankshaft. 9 Clean the seating In the housing and the surface of Ihe crankshaft. Check the crankshaft for burrs which may damage the sealing lip ol Ihe new seal, and If necessary use a Tine file to remove them. 10 Dip the new seal In clean engine oil and carefully locate it over Ihe crankshaft rear flange making sure that it is the correct way round. 11 Progressively tap the oil seal into the housing keeping it square to prevent distortion. A block of wood Is useful for this purpose. 12 Refit the flywheel with reference to Section 11,
8 Cylinder head extension -removal and refitting ^
Removal 1 Remove the timing bolt as described in Soction A. 2 Identify the two HT leads for position then disconnect them from the coil HT terminals. 3 Disconnect the LT wiring plugs from the two ignition coils, then unscrew the mounting bolts and remove the ignition coils from the and of the cylinder head extension {see illustrations). A Undo the bolt and remove the resonator support bracket from Ihe top of the cylinder head extension,
8.8b ... thon remove the cylinder head extension
8.G Unscrew tho protective caps covering the cylinder head extension retaining bolts
5 Unscrew the protective caps covering the cylinder head extension retaining bolts (see Illustration). 6 To retain the cam followers in place as the cylinder head extension Is removed. Flat special tool No 1860988000 will bo required. This tool consists of two strips ol suitably slotted thin metal angle which sDp between the cylinder head extension and cylinder head mating faces as the extension Is lifted off. The tool holds the cam followers in place in the extension allowing the assembly to be withdrawn without fouling the Inlet and exhausl valves, The tools are refetJvety inexpensive and readily available from Fiat dealers. Suitable alternatives can be fabneated, If desired, usrnj thin metal angle strip cut to the dimensions shown (see Tool tip). 7 Progressively slacken and remove the boll$ securing the cylinder head extension to the cylinder head. 8 Lilt tho cylinder head extension up very slightly, keeping it square to the cylindei head. Slip the toots in place to hold the cam followers, then lift the extension off the cylinder head (see illustrations). Recover the gasket between the two assemblies. 9 Dismantling and Inspection procedures lor the cylinder head extension and camshafts are given in Section 9. Refitting 10 Ensure thai Ihe mating faces of the cylinder head and extension aro thorough^ cleaned, with all traces of old gasket removed, then locate a new gasket on Ihe cylinder head (see Illustration).
8.10 Locate a new gasket on the cylinder head
To make a cam follower retaining tool, obtain two lengths of 1hln metal angle and cut both to the dimensions (In mm) shown

2B*9 DOHC (16-valve) petrol engine in-car repair procedures
8.12 Rofit tho cylinder head extension retaining bolts and tighten them to tho specified torque 11 Locate the cam follower retaining tools in position Ihen lower the extension assembly onto the cylinder head. When all the cam followers have engaged their respective valves, remove the tools. 12 Refit tho retaining bolts and tighten them progressively to pull the extension down onto
the
cylinder head. Do this slowly and carefully
as the
vaivo springs will be compressed during Ihfs operation and it is essential to keep the extension square and level as the bolts are lightened. Once all the bolts are Initially Bghloned. progressively tighten them further to
the specified
torque (see illustration). 13 If necessary renew the O-rlng seals on the protective caps covering the cylinder head extension retaining bolts (see illustration).
Refit
the caps and tighten them securoly. 14 Refit the resonator support bracket to the
Icp of
the cylinder head extension.
8.13 Renew the O-ring seals on the protective caps covering the cylinder head extension retaining bolts 15 Refil the ignition coils and reconnect Ihe wiring. 16 Refit the timing belt as described in Section 4.
9 Camshafts and cam ^ followers -
removal,
S inspection and refitting ^
Removal 1 Remove the cylinder head extension as described in Section 8. 2 Place the assembly upside down on a bench and lift off the cam follower retaining tools, 3 Remove the cam followers from their locations In the cylinder head extension and place them In an oil tight compartmented box
labelled 1 to 8 (inlet) and 1 to 8 (exhaust) (see illustration). Alternatively, place them into individual storage jars or containers suitably marked. Fill the box or the jars with clean engine oil until each cam follower is just submerged, 4 Undo the camshaft sprocket retaining bolt while holding the sprocket with a suitable tool as described In Section 4. 5 Remove the camshaft sprocket, then undo the bolt and nut and remove the cover plate over the inlet camshaft (see Illustrations), 6 At the other end of the cylinder head extension, undo the nuts and remove the end cover (soe Illustration). Recover the gasket. 7 Undo the two bolts securing the camshaft drive gears to the inlet and exhaust camshafts (see illustration). The camshaft locking tools used in the timing belt removal procedure (which should still be in place) are sufficient to prevent the camshafts rotating while the gear retaining bolts are undone. Remove the bolts and withdraw the camshaft gears. 8 Remove the camshaft locking tools. 9 Carefully remove the Inlet camshaft from the cylinder head extension (see illustration). Suitably mark the camshaft IN to avoid confusion when refitting. 10 Punch or drill a small hole in the exhaust camshaft oil seal. Screw a self-tapping screw into the hole, and pull on the screw with pliers to extract the seat (soe illustration). 11 Carefully remove Ihe exhaust camshaft from the cylinder head extension (soe illustration). Suitably mark the camshaft EX to avoid confusion when refitting.
JJ Remove the cam followers from their 9.5a Remove the camshaft sprocket... locations in the cylinder head extension
9.5b ... then undo the bolt and nut and remove the cover plate over tho inlet camshaft
9.6 Undo the nuts and remove the end cover
9.7 Undo the two bolts securing the camshaft drive gears to the inlet and exhaust camshafts 9.9 Carefully remove tho Inlet camshaft from the cylinder head extension

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