flat FIAT PUNTO 1998 176 / 1.G User Guide
[x] Cancel search | Manufacturer: FIAT, Model Year: 1998, Model line: PUNTO, Model: FIAT PUNTO 1998 176 / 1.GPages: 225, PDF Size: 18.54 MB
Page 47 of 225

Every 20 000 miles - diesel models ib.h
18
Valve clearance check and
adjustment
1 The Importance of having the valve clearances correctly adjusted cannot be Distressed, as they vitally affect the performance of the engine. Adjustment should only be necessary when the valve gear nas become noisy, after engine overhaul, or when trying to trace the cause of power loss. The clearances are checked as follows. The engine must be cold for the check to be ttcurate. 2 Apply the handbrake then jack up the right-hand front of the vehicle and support on an axle stand (see Jacking and vehicle support). Engage 4th gear. The engine can now be rotated by turning the right-hand front roadwfteei. 3 Remove ail four glove plugs as described In Chapter 5C. 4 Remove the air cleaner cover and air duct
then
remove the camshaft cover as described
in
Chapter 2C. 6 Each valve clearance must be checked wnen the high point of the cam is pointing directly upward away from the cam follower. 6 Check the clearances in the firing order 1-3-4-2, No 1 cylinder being at the timing belt end of the engine. This will minimise the amount of crankshaft rotation required. 7 Insert the appropriate feeler blade between
the heel
of the cam and the cam follower shim of the First valve (see Illustration). If necessary alter the thickness of the feeler blade until it is a stiff, sliding fit. Record the thickness, which will, of course, represent the
vafve
clearance tor Ihis particular valve. 8 Turn the engine, check the second valve devance and record it. t Repeat the operations on all the remaining valves. recording their respective clearances. 10 Remember that the clearance for inlet and exhaust valves differs - see Specifications. Counting from the timing cover end of the
engine,
the valve sequence is: Wef 2-4-5-7 Etfiat/sf 7-3-6-8
11 Where clearances are incorrect the particular shim will have to be changed. To remove the shim, turn the crankshaft until the high point of the cam is pointing directly upward. The cam follower will now have to bo depressed so that the shim can be extracted. Special tools are available from your Fiat dealer to do the job. otherwise you will have to make up a forked lever to locate on the rim of ihe cam follower. This must allow room for the shim to be prised out by means of the cut-outs provided in the cam follower rim (see illustration). 12 Once Ihe shim is extracted, establish Its thickness and change it for a thicker or thinner one to bring the previously recorded clear-ance within specification, For example, if the measured valve clearance was 1.27 mm too great, a shim thicker by this amount will be required. Conversely, if the clearance was 1.27 mm too small, a shim thinner by this amount will be required. 13 Shims have their thickness (mm) engraved on ihem; although the engraved side should be fitted so as not to be visible, wear still occurs and often obliterates the number. In this case, measuring their thickness with a metric micrometer is the only method to establish their thickness (see illustration). 14 In practice, if several shims have to be changed, they can often be interchanged, so avoiding the necessity of having to buy more new shims than is necessary. 15 If more than two or three valve clearances are found to be incorrect, it will be more convenient to remove the camshaft lor easier removal of the shims. 16 Where no clearance can be measured, even with the Ihinnest available shim in position, the valve will have to be removed and the end of its stem ground off squarely. This will reduce its overall length by the minimum amount to provide a clearance. This job should be entrusted to your dealer as it is important to keep the end of the valve stem square. 17 On completion, refit the camshaft cover and gasket, air cleaner and duct, and glosvplugs. 18 Lower the vehicle to the ground.
19 Hinge and lock lubrication
I
1 Lubricate the hinges of the bonnet, doors and tailgate with a light general-purpose oil. Similarly, lubricate all latches, locks and lock stnkers. At the same time, check the security and operation of all the locks, adjusting them if necessary (see Chapter 11). 2 Lightly lubricate the bonnet release mechanism and cable with a suitable grease.
20 Headlight beam adjustment
I
1 Accurate adjustment of the headlight beam Is only possible using optical beam-setting equipment, and this work should therefore be carried out by a Fiat dealer or service station with the necessary facilities. In an emergency, however, the following procedure will provide an acceptable light pattern. 2 Position the car on a level surface with tyres correctly inflated, approximately 10 metres in front of, and at right-angles to, a wall or garage door. 3 Draw a horizontal tine on the wall or door at headlamp centre height. Draw a vertical line corresponding to the centre line of the car. then measure off a point either side of this, on the horizontal line, corresponding with the headlamp centres. 4 Switch on the main beam and check that the areas of maximum Illumination coincide with the headlamp centre marks on the wall. If not, turn the adjustment screw located on the upper Inside edge of the headlight unit to adjust the beam laterally, and the adjustment screw located on the upper outside edge of the headlight unit to adjust the beam vertically. On models with electric headlight adjustment, make sure that it Is set at its basic setting before making the adjustment,
Page 54 of 225

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
4.7 Removing the timing belt cover bottom bolt
7 Unbolt and remove the timing belt cover. Note the bolt located at the bottom of the cover, this can easily be overlooked (see illustration), 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Set the engine al TDC on No 1 cylinder as described in Section 2. 10 Release the nut on the timing belt tensioner, move the lensloner pulley away from the belt and retighten the nut to hold the pulley In the retracted position (see illustration). 11 If the timing belt is to be re-used, use white paint or chalk to mark the direction of rotation on the belt (if markings do not already exist), then slip the bell off the sprockets-Note that the crankshaft and camshaft must not be rotated whilst the belt Is removed. 12 Check the timing belt carefully for any signs of uneven wear, splitting, or oil contamination. Pay particular attention to the roots of the teeth. Renew it if there is the slightest doubt about its condition. If the engine ts undergoing an overhaul, renew the belt as a matter of course, regardless of Its apparent condition. The cost of a new belt is nothing compared with the cost of repairs, should the belt break in sen/ice. If signs of oil contamination are found, trace the source of the oil leak and rectify it. Wash down the engine timing belt area and alt related components, to remove all traces of oil.
Refitting 13 Before refitting, thoroughly clean the timing belt sprockets. Check that Ihe tensioner pulley rotates freely, without any sign of roughness. If necessary, renew the tensioner pulley as described In Section 5. 14 When refitting the new belt, make sure that the sprocket liming marks ore still In alignment and fit the belt so that the arrows on the belt point in the direction of engine rotation, and the lines of the belt coincide with the sprocket marks. 15 Engage the timing belt wilh the crankshaft sprocket first, then place it around the coolant pump sprocket and the camshaft sprocket (see illustration). Finally slip the bell around the tensioner pulley.
II
4.8 Removing the crankshaft pulley
16 Refease the tensioner nut and Insert the laws of a pair of right-angled clmilp pliers (or similar Into the two holes on the front face of the tensioner pulley. Rotate the pulley anticlockwise against the belt until the belt is quite taut. Check lhat the sprocket timing marks have not moved out of alignment. 17 Maintain the effort apptied to the tensioner pulley, then tighten the retaining nut. 18 Turn the crankshaft through two complete turns in the normal direction ot rotation and check that when the centre of (he longest run of the belt Is gripped between finger and thumb It can Just be twisted through 90°. 19 If the belt appears too be too slack or too fight, slacken the tensioner nut and repeat steps 16 to 18 until the correct tension is achieved. Caution: The above procedure serves only as a rough guide to setting the belt tension. The tension must be checked accurately by a Flat dealer using specialised checking equipment, at the earliest opportunity. 20 Refit the timing belt cover, the crankshaft pulley, auxiliary drivebelt(s>, spark plugs and the air cleaner/ducting. Adjust the tension of the auxiliary drivebelt(sl as described In Chapter 1A. 21 Refit the front wheel and lower the car to the ground.
5 Timing belt tensioner % and sprockets - removal, ^ Inspection and refitting ^
Timing beit tensioner
Removal 1 Firmly apply the handbrake, then jock up the front of the car and support it securely on axle stands (see Jacking and vehicle support). Remove the right-hand front roadwheel. 2 Remove the air cleaner and air ducting as described m Chapter 4A or 48, 3 Remove the auxiliary drivebeltfs) as descnbed In Chapter 1A. 4 Undo the three bolts and remove the crankshaft pulley from the sprocket, 5 Unbolt and remove the timing bolt cover. Note the bolt located at the bottom ot the cover, this can easily be overlooked.
4.10 Releasing the timing belt tensioner nut
4.15 Fitting the timing belt
6 Set the engine at TDC on No 1 cylinder as described In Section 2, 7 Loosen the nut on the timing belt tension* and move the tensioner pulley away from the belt (see Illustration), Keep the belt engaged with the sprockets using a cable-tie or string. 8 Completely unscrew the nut and slide Ihe tensioner off Ihe mounting stud. Inspection 9 Wipe the tensioner clean but do not use solvents that may contaminate the bearings. Spin the tensioner pulley on Its hub by hono. Stiff movement or excessive freeplay is w indication of severe wean the tensioner Is not a serviceable component, and should be renewed. Refitting 10 Slide the tensioner pulley over the mounting stud and fit the securing nut.
S.7 Timing bell tensioner retaining nut (arrowed) - shown with timing belt removed
Page 63 of 225

2B*3 DOHC (16-valve) petrol engine in-car repair procedures
2.2s Arrangement of Fiat special tools for setting the piston position and locking the camshafts
arrangement prevents the possibility of the vaivescontacting the pistons when refitting the cinder head or timing belt, and also ensures tet the correct valve timing can be obtained.
The design
of the engine is such that there are n> conventional timing marks on the crankshaft
er
camshaft sprockets to indicate the normal 70C position. Therefore, for any work on the lining belt, camshafls or cylinder head, the b&ng
and
positioning tools must be used.
2 The
special Fiat tools for setting the camshafts and pistons consist of two rods ttikh slide in sleeves that are screwed into
So
t and No 2 cylinder spark plug holes. The
rods are
pushed down to contact the pistons, ird the crankshaft is then turned until both tods protrude from their sleeves by the same enount. With the crankshaft correctly set,
ti»o
camshaft locking pins are used, one for tM inlet camshaft and one for the exhaust earretaft. The pins are screwed into holes on *ach »de of the cylinder head extension so M they engage with slots machined In (he
2.2b Fiat special tool for setting piston position...
camshafts. The arrangement of the Rat special tools are shown (see illustrations). The tool numbers are as follows: Camshaft locking toots Toot No 1860985000 Piston positioning tool Toot No 1860992000
2.2c ... and locking the camshafts
3 Although the special Fiat tools are relatively inexpensive and should be readily available from Flat dealers, it is possible to fabricate suitable alternatives, with the help of a local machine shop, as described below. Once the tools have been made up, their usage Is described In the relevant Sections of this Chapter where the tools are required. Camshaft locking tool fabrication 4 Remove the air cleaner, inlet air duct and resonator as descnbed in Chapter 4B. 5 Unscrew the sealing plug from the front face of the cylinder head extension. 6 Using the sealing plug as a pattern, obtain a length of threaded dowel rod or two suitable bolts to screw into the sealing plug hole. With the help of a machine shop or engineering works, make up the camshaft locking toots by having the dowel rod or bolts machined to the dimensions shown (see illustrations). Note that two will be needed, one for each camshaft.
Suitabt* roll pin (or titling /
ramoviitg
tool
-J 10 h -4 h
AT —
T
—
2,6a To make an alternative camshaft locking tool... 2.6b ... have suitable dowel rods or bolts machined to the dimensions shown
Page 68 of 225

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
Page 83 of 225

Diesel engine in-car repair procedures 2C*11
r
<3^
9.46a The locating dowel in the cylinder block 43 It is possible for the ptston crowns to stnke and damage the valve heads, if the camshaft is rotated v/ith the timing belt removed and the crankshaft set to TDC. For this reason, the crankshaft must be set to a position other than TDC on No t cylinder before the cylinder head is refitted. Use a socket on the crankshaft pulley centre bolt to turn the crankshaft in its normal direction of rotation, until all four pistons are positioned Halfway down their bores, v/ith No 1 piston on lis upstroke - approximately 90° before TDC.
Refitting 44 If the manifolds are being refitted before refitting the cylinder head proceed as follows, otherwise fit the manifolds later when the head is refitted. Ensure thai the inlet and exhaust manifold mating surfaces are completely clean, then locale the new gasket on the studs. 45 Locate the inlet and exhaust manifolds together with the turbocharger, where applicable, on the studs. Refit the nuts and washers and tighten to the specified torque.
sequence
f^/f
9.52b Tighten the cylinder head bolts to the Stage 1 and Stage 2 settings using a torque wrench
on the block 46 Lay the new head gasket on the cylinder block engaging it with the locating dowel. The word ALTO must be uppermost (see illustrations). 47 As a means of locating Ihe cylinder head accurately, cut the heads from two of the old cylinder head bolts. Cut a slot, big enough for a screwdriver blade, in the end of each bolt. These can be used as alignment dowels to assist in cylinder head refitting, however If the head is being refitted without the manifolds it is not necessary to take this action. 48 With the help of an assistant, place the cylinder head assembly centrally on the cylinder block ensuring thai the locating dowels engage with Ihe holes in the cylinder head. Check that the head gasket Is correctly seatod before allowing the full weight of the cylinder head to rest on it. 49 Where necessary, unscrew the home-made alignment dowels, using a flat bladed screwdriver. 50 The oyllnder head bolt threads must be clean. Dip the bolts in engine oil. and allow them to drain for thirty minutes. 51 Carefully enter each bolt with washer into its relevant hole (do not drop them in) and screw in, by hand only, until finger-tight. 52 Working progressively and In the sequence shown, first tighten the cylinder head bolts to their Stage 1 torque setting, using a torque wrench and suitable socket (see illustrations). Go round again, in the sequence shown, and tighten the bolls to the Stage 2 torque setting. 53 Once all the bolts have been tightened to their Stage 2 setting, working again in the
bolts to the Stage 3 and Stage 4 settings
9.46c The word ALTO must be uppermost
given sequence, angle-tighten the bolts through the specified Stage 3 angle, using a socket and extension bar (see illustration). It Is recommended that an angle-measuring gauge is used during this stage of the tightening, to ensure accuracy. If a gauge is not available, use white paint to make alignment marks between the bolt head and cylinder head prior to tightening; the marks can then be used to check tho bolt has been rotated through the correct angle during tightening. Repeat for the Stage 4 setting. 54 Refit the cylinder head front retaining bolts and tighten lo the specified torque. 55 Refit the camshaft cover together with a new gasket and tighten the bolts progressively to the specified torque. 56 The remaining procedure is a reversal of the removal procedure noting the following points. a) Tighten all nut and bolts to the specified torque where given. b) When refitting the metal coolant pipe to the coolant pump, use a new O-ring (see illustration). cj Refit the timing belt with reference to Section 4. d) Use a new exhaust front pipe gasket. e) Refit the auxiliary dhvebeltfs) as described in Chapter 1B. f) Refer to Chapter 4C when refitting the
air
cleaner and air duct. g) Refill the cooling system and fill the engine with new oil with reference to Chapter 1B. 57 Refer to Chapter 20 when starting the engine for the first time.
9.56 Use a new O-ring on the coolant pipe before refitting it to the pump
Page 85 of 225

11.15 Left-hand engine mounting viewed from below 9 lower the engine sufficiently to remove the mounting from the engine bracket. 10 Locate the new mounting in the engine bracket, refit the nut and washers and tighten securely. 11 Raise the engine and refit and tighten the mounting-to-body bolts. 12 Remove the trolley jack and lower the vehicle to the ground. Left-hand mounting 13 If not already done, firmly apply the handbrake, then jack up the front of the car and support It securely on axle stands (see
Jacking
and vehicle support). 14 Place a trolley jack beneath the trans-mission. with a block of wood on the jack head. Raise the jack until it is supporting the weight of the engine/transmission. 15 Unscrew the bolts securing the left-hand mounting to the body (see Illustration). 16 Unscrew the nut securing the mounting to the transmission bracket and recover the washers. 17 Lower the transmission sufficiently to remove the mounting from the transmission bracket. 18 Locate the new mounting in the transmission bracket, refit the nut and washers and tighten securely. 19 Raise the engine and refil and tighten the mounting-to-body bolts. 20 Remove the trolley jack and lower the vehicle to the ground. Rear mounting 21 If not already done, firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see
Jacking
and vehicle support). 22 Working beneath the vehicle, unscrew the bolts securing the rear engine mounting to the underbody (see illustration). 23 Temporarily support the weight of the engine/transmission using a trolley jack. 24 Unbolt the rear mounting assembly from the transmission and withdraw from under the vehicle. 25 Unscrew the bolt and separate the bracket from the mounting. 28 Fitting the new mounting is a reversal of tha removal procedure.
Diesel engine in-car repair procedures 2C*11
11.22 Rear engine mounting viewed from below
12 Sump -removal and refitting
Removal 1 Disconnect the battery negativo terminal (refer to Disconnecting the battery in the Reference Section of this manual). 2 Firmly apply the handbrake, then jack up the front of the car and support it securely on axie stands (see Jacking and vehicle support). 3 Drain the engine oil as described in Chap-ter 1B. Where applicable, remove the screws and lower the engine undertray away from the vehicle. 4 On turbo models disconnect the turbo-charger oil drain hose from the sump (see illustration). 5 Working around the outside of the sump, progressively loosen and withdraw the sump retaining bolts. 6 Break the joint by striking the sump with the palm of your hand, then lower the sump and withdraw it from underneath the vehicle. Recover and discard the sump gasket. 7 While the sump Is removed, take the opportunity to check the oil pump pick-up/strainer for signs of clogging. If necessary, clean or renew the strainer.
Refitting 8 Thoroughly clean the sump inside and out ensuring that all traces of gasket are removed from the mating surfaces of both the sump and the cylinder block/crankcase.
12.4 Turbocharger-to-sump oil drain hose
9 Ensure that the mating surfaces are clean and dry, then apply a little grease to the surface of the sump. This will retain the gasket in position while refitting the sump. 10 Lay the new sump gasket In position on the sump mating surface, then offer up the sump and refit the retaining bolts. Tighten the bolts evenly and progressively lo the specified torque. 11 On turbo models reconnect the turbo-charger oil drain hose. 12 Lower the vehicle to the ground then refer to Chapter 1B and refill the engine with the specified grade and quantity of oil. 13 Reconnect the battery negative terminal.
13 Oil pump and pick-up tube -removal, inspection and refitting
Removal 1 The oil pump Is mounted on the timing belt end of the cylinder block and is driven by flats on the crankshaft nose. Incorporated In the oil pump body is the crankshaft oil seal. 2 Remove the timing belt as described in Section 4, and the crankshaft sprocket as described in Section 5. 3 Remove the sump as described in Section 12. 4 Unscrew the bolts securing Ihe pick-up tube to the bottom of the oil pump. Also unscrew the bolt securing the tube to the No 2 main bearing cap. Withdraw the tube from the oil pump and crankcase. Recover the gasket (see illustrations).
13.4a Removing the oil pump pick-up tube... 13.4b ... and gasket
Page 91 of 225

2D*10 Engine removal and overhaul procedures
1 General information
Included In (his Part of Chapter 2 are details of removing the engine/transmission from the car and general overhaul procedures for tho cylinder head, cylinder block/crankca9e and all other engine internal components. The information given ranges from advice concerning preparation for an overhaul and the purchase of replacement parts, to detailed step-by-step procedures covering removal, inspection, renovation and refitting of engine Internal components. After Section 5, all instructions are based on the assumption that the engine has been removed from the car. For Information concerning in-car engine repair, as well as the removal and refitting of those external components necessary for full overhaul, refer to Part A, 8 or C of this Chapter (as applicable) and to Section 5. Ignore any preliminary dismantling operations described in Part A. B or C that are no longer relevant onca the engine has been removed from ihe car.
2 Engine overhaul -general information
1 It Is not always easy to determine when, or if, an engine should be completely overhauled, as a number of lectors must be considered. 2 High mileage Is not necessarily an Indication that an overhaul Is needed, while low mileage does not preclude the need for an overhaul. Frequency of servicing Is probably the most important consideration. An engine which has had regular and frequent oil and filter changes, as well as other required maintenance, should give many thousands of miles of reliable service. Conversely, a neglected engine may require an overhaul very early In its life. 3 Excessive oil consumption Is an Indication that piston rings, vaivo seals and/or valve guides are in need of attention. Make sure that oil leaks are not responsible before deciding that the rings and/or guides are worn Perform a compression test, as described In Parts A or B (petrol engines) or C (diesel engines) of this Chapter, to determine the likely cause of the problem. 4 Check the oil pressure with a gauge fitted In place of the oil pressure switch. If it Is extremely low. the main and big-end bearings, and/or the oil pump, are probably worn out. 5 Loss of power, rough running, knocking or metallic engine noises, excessive valve gear noise, and high fuel consumption may also point to Ihe need for an overhaul, especially if
they are all present at the same time. If a complete service does not remedy the situation, major mechanical work is the only solution. 6 An engine overhaul involves restoring ell Internal parts to the specification of a new engine. During an overhaul, the cylinders are rebored (where applicable), the pistons and the piston rings are renewed. New main and big-end bearings are generally fitted; If necessary, the crankshaft may be reground. to restore the journals. 7 The valves are also servrced as well, since they are usually In less-than-perfect condition at this point. While the engine is being overhauled, other components, such as the starter and alternator, can be overhauled as well. The end result should be an as-new engine that will give many trouble-free miles. Note: Critical cooling system components such as the hoses, thermostat and coolant pump should be renewed when an engine is overhauled. The radiator should be checked carefully, to ensure that it is not clogged or leaking. A/so. it Is a good Idea to renew the ofI pump whenever the engine i$ overhauled.
8 Before beginning the engine overhaul, read through tho entire procedure, to familiarise yourself with the scope and requirements of the job. Overhauling an engine is not difficult If you follow carefully all of the instructions, have the necessary tools and equipment, and pay close attention to all specifications. It can, however, be time-consuming. Plan on the car being off the road for a minimum of two weeks, especially If pans must be taken to an engineering wo'kd for repair or reconditioning.
9 Check on the availability of parts and make sure that any necessary special tools and equipment are obtained in advance. Most work can be done with typical hand lools, although a number of precision measuring tools are required (or Inspecting parts to determine if they must be renewed. Often the engineering works will handle the inspection of parts and offer advice concerning reconditioning and renewal, Note: Always wait unt'l the engine has been completely dismantled, and until all components (especially the cylinder block/crankcase and the crankshaft) have been inspected, before deciding what service and repair operations must be performed by an engineering works. The condition of these components will be the major factor to consider when determining whether to overhaul the original engine, or to buy a reconditioned unit. Do not. fh ere tore, purchase parts or have overhaul work done on other components until they have been thoroughly Inspected. As a general rule, time is the primary cost of an overhaul, so it does not pay to fit worn or sub-standard parts.
10 As a final note, to ensure maximum life and minimum trouble from a reconditioned engine, everything must be assembled wilh care, in a spotlessly-clean environment.
3 Engine and transmission removal -methods
and
precautions
1 If you have decided that the engine must be removed for overhaul or major repair work, several preliminary steps should be taken. 2 Locating a suitable place to work is extremely important. Adequate work space, along with storage space for the car, will be needed. If a workshop or garage Is not available, at the very least, a flat, level, clean work surface Is required. 3 Cleaning the engine compartment and engine/transmission before beginning the removal procedure wilt help keep tools clean and organised. 4 An engine hoist or A-frame will also be necessary. Make sure the equipment is rated In excess of the combined weight of the engine and transmission, Safety Ib of primary Importance, considering the potential hazards involved in lifting the engine/transmission out of the car. 5 If this is Ihe first time you have removed
an
engine, an assistant Bhould Ideally be available. Advice and aid from someone more experienced would also be helpful. There are many instances when one person cannot simultaneously perform all of the operations required when lifting the engine out of Ihe vehicle. 6 Plan the operation ahead of time. Before starting work, arrange for the hire of or obtain all of the tools and equipment you will need. Some of the equipment necessary to perform engine/transmission removal and Installation safely and wilh relative ease On addition to an engine hoist) Is as follows: a heavy duly trolley jack, complete sets of spanners and sockets as described in the reference section of this manual, wooden blocks, and plenty of rags and cleaning solvent for mopping up spitted oil, coolant and fuel. If the hoist must be hired, make sure that you arrange for it In advance, and perform all of the operations possible without it beforehand. This will save you money and time.
7 Plan for the car to be out of use for quite a while. An engineering works will be required to perform some of the work which the do-it-yourselfer cannot accomplish without special equipment. These places often have a busy schedule, so it would be a good idea to consul! them before removing the engine, in order to accurately estimate the amount of time required to rebuild or repair components that may need work, 9 Always be extremely careful when removing and refitting the engine/transmission. Serious injury can result from careless actions. Plan ahead and take your time, and a job of this nature, although major, can be accomplished successfully.
Page 97 of 225

2D*10 Engine removal and overhaul procedures
4.70 Lowering the engine/transmission assembly to Ihe floor
4.79a Withdraw the Intermediate shaft...
Separation 71 Rest Ihe engine and transmission assembly on a firm, flat surface, and use wooden blocks as wedges to keep the unit steady. 72 Note the routing and location of the wiring
4.77 Removing the transmission lower cover
4.79b ... and recover the dust boot
harness on the engine/transmission assembly, Ihen methodically disconnect It. 73 Remove the starter motor (Chapter 5A). Petrol engines 74 Noto the location of the earth loads on the
4.78 Removing the bolts securing the intermediate shaft to the bracket on the rear of the cylinder block
transmission support bracket on the rear of the cylinder block, then unscrew the securing bolts and move the leads to one side. 75 Unscrew the bolts on the transmission and remove the support bracket. 78 Unscrew tho remaining bolts and remove the transmission lower cover. Diesel engines 77 Unscrew the bolts and remove the transmission lower cover (see Illustration). 78 Unscrew the bolts securing the Intermediate shaft to the bracket on Ihe rear of the cylinder block (see illustration). 79 Withdraw the Intermediate shaft through the bracket and recover the dust boot from tho inner end (see illustrations). 80 Unscrew the mounting bolts and remove the rpm sensor from the transmission (see illustrations). Manual transmission models 81 Support the transmission with blocks ol wood. 82 Unscrew the transmission-to-engine bolts. Also unscrew Ihe nut securing the transmission to the rear ot the cylinder block (see illustrations). 83 Lift the transmission complete with driveshafts directly from the roar of Ihe engine, taking care to keep It level so that the transmission input shaft does not hang on the clutch (see illustration), Automatic transmission models 84 Support the transmission with blocks of wood.
4.83 Separating the engine from tho transmission (petrol engine)
Page 102 of 225

2D*10 Engine removal and overhaul procedures
6.25 Checking the cylinder head for distortion 6.27 Checking the valve guides and valves for wear B.29a Diesel swirl chamber protrusion can be checked using a dial gauge...
scrape off the majority of the deposits with a blunt biade first, then use the wire brush. Caution: Do not erode the sealing surface ot the valve face. 23 Thoroughly clean the remainder of the components using solvent and allow them to dry completely. On 6-valve petrol and diesel engines, discard the oil seals, as new items must be fitted when the cylinder head is reassembled.
Inspection
Cylinder head 24 Inspect the head very carelully for cracks, evidence of coolant leakage, and other damage. If cracks are found, a new cylinder head should be obtained. 25 Use a straight-edge and feeler blade to check that the cylinder head gasket surface is not distorted (see illustration). If it is, it may
be
possible to have it machined, provided that Ihe cylinder head thickness is not excessively reduced. As no specifications as to permissible distortion limits or cylinder head thickness tolerances are given by ihe manufacturer, seek the advice of an engine overhaul specialist if distortion Is apparent. 26 Examine the valve seats In each of the combustion chambers, If they are severely pitted, cracked, or burned, they will need to be renewed or re-cut by an engine overhaul specialist. If they are only slightly pitted, this can be removed by grinding-in the valve heads and seats with fine valve-grinding compound, as described below.
27 Check the valve guides for wear by inserting the relevant valve, and checking for side-to-side motion of the valve (see illustration) A very small amount of movement Is acceptable. If the movement seems excessive, remove the valve. Measure the valve stem diameter at several points, and renew the valve if it is worn. If the valve stem is not worn, the wear must be In the valve guide, and the guide must be renewed. The renewal of valve guides should be earned out by an engine overhaul specialist, who will have the necessary tools required. 26 If renewing the vaive guides, the valve seats should be re-cut or re-ground only after the new guides have been fitted. 29 On diesel engines, inspect the swirl chambers for burning or damage such as cracking. Smalt cracks in the chambers are acceptable: renewal of the chambers will only be required if chamber tracts are badly burned and disfigured, or if they are no longer a tight fit in the cylinder head. If there is any doubt as to the swirl chamber condition, seek the advice of a Flat dealer or a suitable repairer who specialises in diesel engines. Swirl chamber renewal should be entrusted to a specialist. Using a dial test indicator, check that the difference between the swirl chamber and the cylinder head surface is within the limits given in Ihe Specifications. Alternatively feeler blades and a straight-edge may bo used (see illustrations). Zero the dial test indicator on the gaskel surface of tho cylinder head, then measure the protrusion of the swirl
chamber, if the protrusion is not within the specified limits, the advice of a Fiat dealer or suitable repairer who specialises in diesel engines should be sought. Camshaft 30 Inspect the camshaft for wear on the surfaces of the lobes and journals. Normally their surfaces should be smooth and have a dull shine: look for scoring and pitting. Accelerated wear will occur once the hardened exterior of the camshaft has been damaged. 31 Examine the bearing cap and journal surfaces for signs of wear. 32 To measure the camshaft endfloat, temporanly refit the camshaft then push the camshaft lo one end of the cylinder head as far as It will travel. Attach a dial test indicator to the cylinder head and zero it, then push the camshaft as far as It will go to the other end of the cylinder head and record the gauge reading. Verify the reading by pushing the camshaft back to its original position and checking that the gauge indicates zero again (see Illustration). 33 The camshaft bearing running clearance may be checked using Plastigauge as described later in this Chapter. 34 Where the camshaft and bearings are worn excessively consider renewing the complete cylinder head together with camshaft and cam followers. A reconditioned head may be available from ongine repairers. Wear of cam followers may be checked using a micrometer (see illustration).
6.29b ... or feeler blades 6.32 Chocking the camshaft endfloat with a dial gauge 6.34 Checking the wear of the cam followers
Page 103 of 225

2D*10 Engine removal and overhaul procedures
Valves and associated components 35 Examine the head of each vaive for pitting, burning, cracks, and general wear. Check the valve stem for scoring and wear ridges. Rotate the valve, and check lor any obvious indication that it Is bent. Look tor pits or excessive wear on the tip of each valve stem. Renew any valve that shows any such signs of wear or damage. 36 if the valve appears satisfactory at this stage, measure the vaive stem diameter at several points using a micrometer. Any significant difference in the readings obtained Indicates wear of the valve stem. Should any of these conditions be apparent, the valve(s) must be renewed. 37 If the valves are In satisfactory condition, they should be ground (lapped) into their respective seats, to ensure a smooth, gas-tight seal. If the seat is only tightly pitted, or if it has been re-cut, fine grinding compound only should be used to produce the required finish. Coarse valve-grinding compound should nor be used, unless a seat is badly bumed or deeply pitted, If this is the case, the cylinder head and valves should be Inspected by an expert, to decldo whether seat re-cutting, or even the renewal of the valve or seat insert (where possible) is required. 38 Valve grinding Is carried out as follows. Place the cylinder head upside-down on blocks on a bench. 39 Smear a trace of (the appropriate grade of) valve-gnndtng compound on the seat face, and press a suction grinding tool onto the valve head. With a semi-rotary action, grind
6.48 Compressing the vaive spring and fitting the split collets
them
the valve head to its seat, lifting the valve occasionally to redistribute tho grinding compound (see Illustration). A light spring placed under the valve head will greatly ease this operation 40 If coarse grinding compound Is being used, v/ork only until a dull, matt even surface Is produced on both the valve seal and the valve, then wipe off tho used compound, and repeat the process with fine compound. When a smooth unbroken ring ol light grey malt finish Is produced on both the valve and seat, the grinding operation is complete. Do not grind-In the valves any further than absolutely necessary, or the seat will be prematurely sunk into the cylinder head. 41 When all the valves have been ground-m, carefully wash off all traces of grinding compound using paraffin or a suitable solvent, before reassembling the cylinder head. 42 Examine the valve springs for signs of damage ano discoloration, If possible compare the length of the springs with new ones and renew them if necessary. 43 Stand each spring on a flat surface, and check ft tor squareness. If any of the springs are damaged, distorted or have lost mar tension, obtain a complete new set of springs. It Is normal to renew the valve springs as a matter of course if a major overhaul is being earned out. 44 Renew (he valve stem oil seals regardless of their apparent condition.
Reassembly 45 Lubricate the stems of the valves, and insert the valves into their original locations
6.53 Tightening the camshaft bearing cap nuts (diesel engines)
6.46 Using a socket to press the valve stem seals onto the guides
(see illustration). If new valves are being fitted, insert them Into the locations to which they have been ground. 46 Refit the spring sea( then, working on the first valve, dip the new valve stem sesl in fresh engine oil. Carefully locate it over the valve and onto the guide. Take care not to damage the seal as it Is passed over the valve stem. Use a suitable socket or metal tube to press the seal firmly onto the guide (sea Illustration). 47 Locate the valve spring on top of its seat, then refit the spring retainer. 48 Compress the valve spring, and locate the split collets in the recess in the valve stem. Release the compressor, then repeat the procedure on the remaining valves (see illustration)
Use a dab o) grease to hold Uiejitts* the collets In position on the HlNT valve stem while the spring compressor is released.
49 With ail the valves Installed, place the cylinder head on blocks on the bench and, using a hammer and Interposed block ol wood, top the end of each valve stem to settle the components. 50 On diesel engines, refit the swirl chambers together with their washers and tighten the retaining collars to the specified torque. 51 Oil the cam followers and locate them In their correct positions in the cylinder head. Locate the shims In the cam followers making sure they are in their original positions. 52 Oil the journals then locate the camshaft m the cylinder head with the cam lobes of No 1 cylinder facing upwards (ie No 1 cylinder at TDC). 53 Refit the bearing caps In their correct positions and progressively tighten the nuts/bolts to the specified torque (sea illustration). On petrol engines locate the lubrication pipe on Ihe head and press in the oil feed stub before refitting the bolts. 54 On diesel engines fit a new oil sea) to the right-hand side mount, then refit both side mounts together with new gaskets, Tighten the right-hand mount bolts. Also refit the coolant cover and thermostat housing together with new gaskets (see illustrations).