1998 FIAT PUNTO Head

2D*10 Engine removal and overhaul procedures
Engine and transmission -removal, separation, connection and refitting
Note: The engine Is lowered from the engine compartment as a complete unit with the transmission; tho two are then separated for overhaul.
Removal 1 Remove the bonnet and disconnect the washer tubing as described in Chapter 11 (see illustrations). 2 Apply the handbrake, then jack up the front of the vehicle and support on axle stands (see Jacking and vehicle support). Remove both front wheels. In order to remove tne engine/transmission assembly in an upright position from under the vehicle, there must be a minimum clearance of 660 mm between the floor and the front crossmember. Additional height Is necessary if the assembly is to be lowered onto a trolley. 3 Where fitted, unbolt and remove the engine compartment lower cover. 4 Remove the auxiliary drivebelt(s) with reference to Chapter 1A or 1B. 5 Dram the engine oil. transmission oil/fluid and coolant with reference to Chapter 1A or 1B. 6 Remove the battery (see Chapter 5A). 7 On manual transmission models with a cable dutch, disconnect the clutch cable from the transmission (refer to Chapter 6). On manual transmission models with a hydraulic clutch unbolt the clutch slave cylinder from the top of the transmission then fit a cable-tie around it to prevent the piston coming out (see Illustration). Position the cylinder to one side. 8 Unscrew the nut and disconnect the earth lead from the transmission (see illustration). Petrol engines 9 Unbolt and remove the battery tray. 10 Disconnect the wiring from the reversing light switch. 11 On manual transmission models disconnect the reverse Inhibition cable from the transmission then disconnect the gear selector rod from the lever on the transmission. 12 Remove the air cleaner and ducting as descnbed In Chapter 4A or 4B. 13 On automatic transmission models disconnect the kickdown cable and gear selector cable as described in Chapter 7B. Also disconnect the wiring for the electro-magnetic clutch. 14 Unbolt and remove the cover from the bulkhead then disconnect the oxygen sensor wiring. 15 Disconnect the remaining wiring at the bulkhead and release the fuse holders at the mounting. 16 Disconnect the vacuum pipe from the inlet manifold, and also disconnect the wiring connector located next to it.
4.1a Unscrewing the bonnet hinge bolts
17 Unscrewthenutsandseparatetheengine wiring harness lead from the battery positive cable terminal. 18 Disconnect the accelerator cable from the engine as described in Chapter 4A or 4B, 19 Loosen the clip and disconnect the radiator top hose from the elbow on the left-hand end of the cylinder head. Similarly disconnect the bottom hose. On 16-valve models, remove the radiator electric cooling fan as described in Chapter 3. 20 Identify the hoses connected to the throttle housing, then disconnect them. 21 Identify the coolant heater hoses on the bulkhead for position, then loosen the clips and disconnect the hoses. 22 Loosen the clip and disconnect the brake servo vacuum hose from the Inlet manifold. Where applicable, disconnect the remaining emission control system vacuum hoses from the Inlet manifold after Identifying their locations to aid refitting. 23 Disconnect tho fuel supply and return hoses from the throttle housing. 24 Release the connector from the ignition/fuel ECU located on the right-hand side of the engine compartment. 25 Unscrew the nut and detach the earth cable from its location near the ECU. 26 Disconnect the diagnostic connector located near the ECU. 27 On models fitted with power steering, refer to Chapter 10 and unbolt the power steering pump from the front of the engine without disconnecting the hydraulic fluid lines then tie It to one side so that it will not obstruct the removal of the engine. On
4.1b Disconnecting the washer tubing
models with air conditioning, similarly unbolt the air conditioning compressor and position it clear of the engine. Do not disconnect the air conditioning refngerant pipes/hoses. 26 On manual transmission models pull out the retaining plate and disconnect the gear selector cable from the lever on the transmission. 29 Unscrew the nuts retaining the track rod ends on the swivel hubs and use a balljoint separator tool to disconnect them. 30 Release the flexible brake fluid hoses and ABS system sensor wrring from the front suspension struts. 31 On manual transmission models, unscrew the nuts from the outer ends of each driveshaft. To prevent the hubs from turning either have an assistant depress the brake pedal, or temporarily Insert two wheel bolts and use a lever to hold the hub. 32 On automatic transmission models use a suitable drift to drive out Ihe roll pins securing 2D the inner ends of the drlveshafts to tho trans-mission output stubs. Turn the driveshalts as necossary to access the roll pins . 33 Unscrew the two bolts securing the right-hand swivel hub assembly to the front suspension strut, then move the hub assembly outwards. On manual transmission models release the outer end of the driveshaft from the hub assembly - on automatic transmission models slide the inner end of the driveshaft off the final drive output stub. Take care not to strain the flexible brake hose while doing this. Move the driveshaft to one side thon temporanly refit the hub assembly to the strut. On manual transmission models, make
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4.7 Fit a cable tie around the dutch slave cylinder to prevent the piston coming out 4.8 Disconnecting the earth lead from the transmission

2D*10 Engine removal and overhaul procedures
4.36a Relay guard mounting nuts 4.36b Battery tray and mounting bolts 4.36c Disconnect the engine wiring harness located above the transmission .
4.36d ... the inner wiring plug ...
sure that the dnveshaft is positioned to clear Ihe lower suspension arm when the engine is removed. 34 Disconnect the left-hand driveahaft using the same procedure
4.41 Engine wiring harness connections to the battery positive cable
4.36e ... and the outer wiring plug
35 Remove the exhaust front downpipe witfl reference to Chapter 4D. Diesel engines 36 Unbolt and remove the roiay guard then disconnect the wiring as applicable and unbolt the battery tray (see Illustrations). 37 Disconnect tho gear selector cable from the transmission by removing the retaining plate and prising the socket end off Ihe ball on the lever. Use a pair of pliors to pull out the plate. Tie the cable to the bulkhead (see illustration). 38 Unscrew the nut and disconnect the gear selector rod from the ievor on the top of the transmission, 39 Remove the air cleaner and air inlet duct by unscrewing the two bolls securing the duct to the valve cover and loosening the clip securing the duct to the air cleaner. Refer to Chapter 4C if necessary.
4.37 Tie tho gear selector cable to the bulkhead
40 Disconnect the vacuum pipe from the vacuum pump on the left-hand side of the cylinder head and disconnect the wiring plug located over the transmission, 41 Unscrew ihe nuts and disconnect the engine wiring harness from the battery positive cable (see illustration) 42 At the fuel filter unscrew the union bolt and disconnect the fuei delivery hose lor the injection pump. Use polythene and an elastic band to cover the end of the hose (see illustrations). 43 At the fuel injection pump unscrew the clip and disconnect thie fuel return hose (see illustration). 44 Disconnect the radiator top hose from the thermostat housing on tho left-hand side of the cylinder head, and also disconnect the healer hose at Ihe engine (see illustrations). 45 Disconnect the heater return hose and expansion tank hose from the elbow on the
4.42a Unscrew the union bolt and disconnect the fuel delivery hose from the fuel filter 4.42b Cover the end of the hose to prevent dust entry 4.43 Disconnecting the fuel return hose from the fuel injection pump

2D*10 Engine removal and overhaul procedures
4.44a Disconnecting tho radiator top hose from the thermostat housing
4.45b ... and expansion tank hose
lofi-nand side of the cylinder head, From the top ot the radiator and from the expansion tank (see Illustrations). 46 Disconnect the radiator bottom hose from the elbow on the cylinder head.
4.49e ... and the adjustment lockbolt...
4.44b Disconnecting the heater hose st the engine
4.49a Remove the front bracket bolt...
47 On models with a speedometer cable, disconnect the cable from the transmission. 48 On models with an electronic speedometer, if necessary disconnect the winng connector on the support bracket. The cable may be left
4.49f ... and tie the power steering pump to the bulkhead
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4.45a Disconnecting the heater return hose...
4.49b ... the belt adjustment bolt...
attached if Ihe transmission Is not being detached from the engine. 49 On models fitted with power steering, unbolt the power steering pump from the rear right-hand side of the engine without disconnecting the hydraulic fluid lines then tie it to one side on the bulkhead so that it will not obstruct the removal of the engine. To do (his first remove the front bracket bolt, remove the belt adjustment bolt, remove the rear through-bolt, lift away the cover and remove the adjustment lockbolt (see illustrations). On models with air conditioning, similarly unbolt the air conditioning compressor and position It clear of the engine. Do not disconnect the air conditioning refrigerant pipes/hoses. 50 Disconnect the coolant purge hoses from the top of the radiator and expansion tank (seo illustrations). 51 Disconnect the accelerator cable from the injection pump (see Chapter 4Q.
4.50a Disconnecting the coolant purge hoses from the radiator...

2D*10 Engine removal and overhaul procedures
60 At the otl filter, unscrew the union nuts and disconnect the oil cooler lines/hoses then remove the oil cooler from the vehicle (see Illustration). Be prepared for some oil leakage. Note the fitted position of the hoses before disconnecting them so that they can be refitted correctly. 61 Disconnect the reversing light wiring from Ihe switch on the front of the transmission (see illustration) 82 Using an Allen key, unscrew the bolts securing the inner ends of the driveshafts to the flanges on the transmission. The right-hand driveshaft is disconnected from the Intermediate shaft flange on the rear of the engine. Recover the plates beneath the heads ol the driveshaft bolls (see illustrations). 63 Unscrew the bolts securing the front sv/lvel hub assemblies to the struts. Also
4.59c Removing the radiator from the vehicle
4.62a Use an Allen key to unscrew the inner driveshaft bolts
release the flexible brake hoses from the struts. 64 Move the swivel hub assemblies outwards and support the inner ends of the dnveshafts on axle stands (see Jacking and vehicle support). Take care not to strain the flexible brake hoses. 65 Remove the exhaust front pipe with reference to Chaptor 4D. If difficulty is expenenced in separating Ihe front pipe from the intermediate pipe, it may prove easier to remove the complete exhaust system. Ail models 66 Attach a suitable hoist to the engine and transmission lifting eyes (see illustration). The left-hand eye is located on the transmission and the right-hand one on the right-hand side of the engine, Take the weight of the engine/transmission.
4.60 Loosening the union nuts securing the oil cooler lines to the oil filter housing
4.62b Removing the driveshaft bolts and plates
67 Working boneath the vehicle, unscrew the bolts securing tne rear engine mounting to the underbody and transmission, and withdraw the mounting. 68 In the engine compartment, unscrew the bolts securing the right-hand engine mounting to the body and engine. For additional working room completely remove the mounting. 69 Unscrew the boils securing the left-hand engine/transmission mounting to the body. For additional working room completely remove Ihe mounting. 70 With the help of an assistant lower the engine/transmission from the engino compartment taking care not to damage the surrounding components (see illustration). Ideally lower the unit onto a low trolley so that it may be withdrawn from under the vehicle. Disconnect the hoist from ihe assembly.
4.61 Disconnecting the reversing light wiring
4.66 Attaching a hoist to tho ongine and transmission assembly

2D*10 Engine removal and overhaul procedures
6.5s Prising out the feed stub of the camshaft lubricating pipe J) Flywheel (Chapter 2C). k) Clutch components (Chapter
6).
I) Cooling system components (Chapter
3).
Note: When removing trie external components from the engine, pay close attention to details that may be helpful or important during refitting. Note the fitted position of gaskets, seals, spacers, pins, washers, bolts, and other small components. 4 If you are obtaining a short engine (the engine cylinder block/crankcase, crankshaft, pistons and connecting rods, all fully assembled), then the cylinder head, sump, oil pump, timing belt (together with its tensloner and covers), coolant pump, thermostat housing, coolant outlet elbows, oil filter housing and where applicable oil cooler will also have to be removed. 5 If you are planning a full overhaul, the engine can be dismantled in the order given below: $) Ftywhaoi/drivoplate.
6.5d When removing the camshaft bearing caps, note the position of the (ong and short locating dowels
bearing/banjo union bolt b) Timing belt, sprockets, and tensioner. c) Inlet and exhaust manifolds. d) Cylinder head. e) Sump. f) Oil pump. g) Pistons and crankshaft.
6 Cylinder head - % dismantling, cleaning, inspection and reassembly ^
Note: Now and reconditioned cylinder heads are available from the manufacturer or engine overhaul specialists. Be aware that some specialist tools are required for the dismantling and inspection procedures, and new com-ponents may not be readily available. It may therefore be mors practical and economical for the home mechanic to purchase a reconditioned head, rather than dismantle, inspect and recondition the original head.
Dismantling Note: On 8-valve petrol engines and diesel engines, the camshaft and cam followers are /oca fed In the cylinder head assembly and the relevant dismantling and reassembly procedures are contained in this Section. On 1$-valve petrol engines, the camshafts and cam followers are /oca fed In a separate housing (cylinder head extension) which is bo/fed fo the top of the cylinder head. All procedures relating to the camshafts and cam followers on 16-valve engines are therefore contained in Chapter 2B. Proceed fo paragraph 15 for cylinder head dismantling
6.8a Unscrew and remove the bolts from the thermostat housing, noting the location of the bracket
6.5c Removing the camshaft lubricating pipe procedures on /6-vafve engines, and ignore any references to camshafts, cam followers and oil seals in the paragraphs that follow. 1 Remove the cylinder head as described in Part A. B or C of this Chapter (as applicable). 2 If not already done, remove the inlet and exhaust manifolds with reference to the relevant Part of Chapter 4. Also remove the spark plugs, glow plugs and injectors as applicable. 3 Remove the camshaft sprocket with reference to Chapter 2A or 2C. Petrol engines 4 Mark the positions of the camshaft bearing caps, numbering them from the timing end. 5 Unbolt and remove the lubrication pipe (prise the oil feed stub out with a screwdriver). Unscrew the remaining bolts and take off the bearing caps (see illustrations). 6 Lift the camshaft carefully from the cylinder head, checking lhat the valve clearance shims and cam followers are not withdrawn by the adhesion of the oil (see Illustration). 7 Remove the shims and cam followers, but keep them In their originally fitted order. Diesel engines 8 Unbolt the thermostat housing and gasket, and vacuum pump from the left-hand end of the cylinder head. Also if necessary unbolt the coolant cover and gasket from the right-hand end of the head. Note the location of brackets (see illustrations) 9 Using a soft metal drift, carefully lap out the left-hand side mount and recover the gasket (soe illustrations). 10 At tho timing bait end of the cylinder head.
6.8b Removing the thermostat housing ... 6.6 Removing the camshaft

2D*10 Engine removal and overhaul procedures

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6.8c ... and gasket
unscrew the bolts securing the right-hand Side mount to the head. Carefully tap out the right-hand side mount and recover the gasket (see illustrations). 11 Mark the positions of the camshaft bearing
6.10a Removing tho camshaft right-hand side mount...
6.12b ... and remove the bearing caps
6.8d Unscrew the vacuum pump mounting nuts noting the location of the bracket
caps, numbering from the timing belt end. 12 Progressively unscrew the bearing cap nuts then take off the bearing caps. Note the location dowels on the mounting studs (sae Illustrations).
6.12c The camshaft mounting studs incorporate location dowels
6.8e Removing the vacuum pump
13 Lift the camshaft towards the timing end. then remove it from the cylinder head (see illustration). Make sure the valve clearance shims and cam followers are not withdrawn by the adhesion of the oil.
6.13 Removing the camshaft from the cylinder head
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2D*10 Engine removal and overhaul procedures
6,14a Removing the shims... 6.14b ... and cam followers 6.16a Removing the upper spring seat...
14 Remove Ihe shims and cam followers, but keep them In their onginally fitted order (see illustrations) All engines 15 Stand the cylinder head on its end. Using a valve spring compressor, compress each valve spring in turn, extracting the split collets when the upper valve spring seat has been pushed far enough down the valve stem to free them. If the spring seat sticks, lightly lap Ihe upper |aw of the spring compressor with a hammer to free It. 16 Release tho valve spnng compressor and remove the upper spring seat, valve spring and lower spring seat (see illustrations) 17 Withdraw the valve from the head gasket side of the cylinder head, then use a pair of pliers to extract the valve stem oil seal from the top of the guide (see illustrations). If the
valve slicks In the guide, carefully deburr the end face wilh fine abrasive paper. Repeat this process for the remaining valves. 18 On diesel engines, if Ihe swiri chambers are badly coked or burned and are in need of renewal, they may be removed by unscrewing the retaining collars and carefully tapping them out from the combustion chamber side. Recover the washers and keep them identified for position (see illustration). 19 It is essential that each valve is stored together with Its collets, retainer, spring, and spring seat. The valves should also be kept in (heir correct sequence, unless they are so badly worn that they are to be renewed. If they are going to be kepi and used again, place each valve assembly in a labelled polythene bag or similar small container (see Illustration). Note that No 1 valve is at the timing belt end of Ihe engine.
Cleaning 20 Using a suitable degreasing agent, remove all traces of oil deposits from the cylinder head, paying particular attention to tho journal bearings, cam follower bores, valve guides and oilways. as applicable. Scrape off any traces ot old gasket from the mating surfaces, taking care not to score or gouge them. If using emery paper, do not use a grade of (ess than 100. Turn the head over and using a blunt blade, scrape any carbon deposits from the combustion chambers and ports. Caution: Do not erode the seeling surface of tho valve seat. 21 Finally, wash the entire head casting with a suitable solvent to remove the remaining debns. 22 Clean the valve heads and stems using 8 fine wire brush. If the valve is heavily coked,
5.18 Swirl chamber retaining collar (diesel engine) 6.19 Keep groups of components together in labelled bags or boxes

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