Idle FIAT PUNTO 1998 176 / 1.G User Guide

Component location - diesel models ib-s
Rear underbody view - turbo diesel model
1
Fuel tank
2
Exhaust
tailpipe
and
silencer 3 Fear axle 4 Coil springs 5
Rear anti-roll bar
€
Handbrake cables
7
Rear brake pressure regulating valve
8
Rear shock
absorber
lower
mountings
Maintenance procedures
1 Introduction
This Chapter Is designed to help the home mechanic maintain his/her vehicle for safety, economy, long life and peak performance. The Chapter contains a master maintenance schedule, and Sections dealing specifically with each task in the schedule. Visual checks, adjustments, component renewal and other helpful items are included. Refer to the accompanying illustrations of the engine compartment and the underside of the vohicle for the locations of the various components. Servicing your vehicle in accordance with ihe mileage/time maintenance schedule and the following Sections will provide a planned maintenance programme, which should result in a long and reliable service life. This is a comprehensive plan, so maintaining some items but not others at the specified service internals, will not produce the same results. As you service your vehicle, you will ctecover that many of the procedures can. and should, be grouped together, because of the particular procedure being performed, or because of the proximity of two otherwise-unrelated components to one another. For example, if the vehicle is raised for any reason, the exhaust can be inspected at the same time as the suspension and steering components. The first step in this maintenance programme is to prepare yoursetf before the
actual work begins. Read through all the Sections relevant to the work to be carried out. then make a list and gather all the parts and tools required. If a problem is encountered, seek advice from a parts specialist, or a dealer service department.
2 Regular maintenance
1 If, from the time Ihe vehicle is new, the routine maintenance schedule is followed closely, and frequent checks are made of fluid levels and high-wear Items, as suggested throughout this manual, the engine wifl be kept in relatively good running condition, and the need for additional work will be minimised. 2 It is possible that there will be times when the engine is running poorly due to the lack of regular maintenance. This is even more likely if a used vehicle, which has not received regular and frequent maintenance checks, is purchased, in such cases, additions! work may need to be carried out, outside of the regular maintenance intervals. 3 If engine wear is suspected, a compression test {refer to Chapter 2C} will provide valuable information regarding the overall performance of the main internal components. Such a test can be used as a basis to decide on the extent of the work to be carried out. If, for example, a compression test indicates serious Internal engine wear, conventional maintenance as
described in this Chapter will not greatly improve the performance of the engine, and may prove a wa3te of time and money, unless extensive overhaul work Is carried out first. 4 The following series of operations are those usually required to Improve the performance of a generally poor-running engine:
Primary operations a,I Clean, Inspect and test the battery (See Weekly checks). b) Check all the engine-related fluids (See Weekly checks). c) Drain the water from the fuel filter (Section 4) d) Check the condition and tension of the auxiliary dnvebeft(s) (Section 16). e) Check the condition of the air fitter, and renew if necessary (Section 13). f) Check the condition of all hoses, and check for fluid leaks (Section 8). g) Check the engine idle speed setting {Section 11). h) Check the exhaust gas emissions (Section 25). 5 If the above operations do not prove fully effective, carry out the following secondary operations:
Secondary operations All items listed under Pnmary operations, plus the following: a) Check the charging system (Chapter 5A, Section 4). b) Renew the fuel filter (Section 12) and check the fuel system (see Chapter 4Q.

ib-8 Every 10 000 miles - diesel models
10.1 Checking the condition of a driveshaft gaiter
9 Exhaust system check
1 With the engine cold {at least an hour after tho vehicle has been driven), check ihe complete exhaust system from the engine to the end of the tailpipe. The exhaust system Is most easily checked with the vehicle raised on a hoist, or suitably supported on axle stands (see Jacking and vehicle support), so that the exhaust components are readily visible and accessible. 2 Check the exhaust pipes and connections for evidence of leaks, severe oorrosion and damage. Make sure that all brackets and mountings are In good condition, and that all relevant nuts and bolts are tight, Leakage at any of the joints or in other parts of tho system will usually show up as a black sooty stain in the vicinity ot the leak. 3 Rattles and other noises can often be Iracod to the exhaust system, especially the brackets and mountings. Try to move the pipes and silencers. If the components are able to come into contact with the body or
suspension parts, secure the system with new mountings. Otherwise separate the joints (if possible) and twist the pipes as necessary to provide additional clearance.
10 Driveshaft gaiter check
I
1 With the vehicle raised and securely supported on stands (see Jacking and vehicle support), turn the steering onto lull lock, then slowly rotate the roadwheel. Inspect the condition ol the outer constant velocity (CV) joint rubber gaiters, squeezing the gaiters to open out the folds. Check for signs ot cracking, splits or detenoration of the rubber, which may allow the grease to escape, and lead to water and grit entry into the joint. Also check the security and condition of the retaining clips. Repeat these checks on the Inner CV joints (see illustration). If any damage or deterioration is found, the gaiters should be renewed (see Chapter 8. Section 3). 2 At the same time, check the general condition of the CV joints themselves by first holding the driveshaft and attempting to rotate the wheel. Repeat this check by holding the inner joint and attempting to rotate the driveshaft. Any appreciable movement indicates wear in the joints, wear in Ihe driveshaft splines, or a loose driveshaft retaining nut.
11 Idle speed check and adjustment
1 The usual type of tachometer (rev counter), which works from ignition system pulses, cannot be used on diesel engines. A
diagnostic socket is provided for the use of Flat test equipment, but this will not normally be available to the home mechanic. If it Is not felt that adjusting the Idle speed by ear 19 satisfactory, It will be necessary to purchase or hire an appropriate tachometer, or else leave tho task to a Fiat dealer or other suitably equipped specialist, 2 Before making adjustments, warm up the engine to normal operating temperature. Make sure that the accelerator cable is correctly adjusted (see Chapter 4C). 3 The adjustment must be made with all electrical components (Including the cooling fan) switched off. It the fan comes on dunng the adjustment, wait until it switches off automatically before proceeding. 4 The idle adjustment screw Is located on the top of the fuel injection pump (see illustration). To adjust the idie speed loosen the locknut and turn the screw as required then tighten the locknut. 5 On completion switch off the engine.
12 Fuel filter renewal i
1 The fuel filter is located on the bulkhead in the engine compartment. An electrically-operated heater is located between the filter and tlw housing, 2 Position a suitable container under the fuel filler. Loosen tho bleed screw on the top of the filter, then disconnect the wiring from Ihe water sensor and loosen the water drain screw on the bottom of the filter. Allow the fuel to drain completely (see illustration). 3 Tighten the drain and bleed screws, then Use an oii niter strep to loosen the fuel filter {see illustration).
12.2 Loosening the bleed screw on the top of the fuel filter
11.4 fdie speed adjustment 1 Locknut 2 Adjustment screw

ib-io Every 10 000 miles - diesel models
7 With the car standing on Its wheels, have an assistant turn the steering wheel back and forth about an eighth of a turn each way. There should be very hide. If any, lost movement between the steering wheel and roadwheels. If this is not the case, closely observe the joints and mountings previously described, but in addition, check the steering column universal joints for wear, and the rack-and-plnion steering gear itself.
Suspension strut/ shock absorber check 8 Check for any signs of fluid leakage around the suspension strut/shock absorber body, or from the rubber gaiter around the piston rod, Should any fluid be noticed, the suspension strut/shock absorber is defective Internally, and should be renewed. Note: Suspension struts/shock absorbers should always be renewed in pairs on the same axle.
9 The efficiency of the suspension strut/shock] absorber may be checked by bouncing 0*1 vehicle at each comer. Generally speaking. th»| body will return to its normal position and 8top| after being depressed. If It rises and returns cn| a rebound, the suspension strut/shocH absorber is probably suspect. Examine also* the suspension strut/shock absorber uppeij and lower mountings for any signs of wear.
Every 20 000 miles (30 000 km) or 2 years
18 Auxiliary drivebeltfs) % check and renewal
Note: Fiat specify the use of a spec/a/ toot to correctly set the drivebelt fens/on. if access to this equipment cannot be obtained, an approximate setting can be achieved using the method described beiow. If the method described Is used, the tension should be checked using the spec/a/ too! at the earliest possible opportunity. 1 Depending on equipment fitted, one, two or three auxiliary drivebeits may be fitted. The alternator, power steering pump and air conditioning compressor, as applicable, are each driven by an individual drivebelt. Checking 2 Disconnect the battery negative terminal (refer to Disconnecting the battery In the Reference Section of this manual). 3 Firmly apply the handbrake, then Jack up the Iront of the car and support it securely on exie stands (see Jacking and vehicle support). 4 Remove the right-hand wheel. 5 Remove the Inner cover(s) from under the right-hand wheelarch for access to the right-hand side of the engine. 6 Using a socket on the crankshaft sprocket bolt, rotate the crankshaft so that the full length of the auxiliary drivebelt(s) can be examined. Look for cracks, splitting and fraying on the surface of the belt: check also for signs of glazing (shiny patches) and
16.10a Loosening the alternator drivebelt adjustment bolt
separation of the belt plies. If damage or wear Is visible, the bell should be renewed, 7 If the condition of the belt Is satisfactory, check tho drivebelt tension as described below.
Renewal
Alternator drivebelt 8 On models with air conditioning, remove the compressor drivebelt as described below, 9 Unclip and remove the upper timing belt cover, then unbolt end remove the lower timing belt cover. 10 Loosen the pivot bolt and adjustment lockbolt then unscrew the adjustment bolt to move the alternator towards the engine so that the drivebelt may be slipped off the alternator, crankshaft, and, on models with air con-ditioning, the Idler pulley (see Illustrations), 11 When renewing a drivebelt. ensure that the correct type is used. Fit the belt around the pulleys then tighten the adjustment bolt to take up any slsck In the belt. Adjust the tension correctly as described below. Power steering pump drivebelt
12 Remove the alternator drivebelt as described previously. 13 Slacken the bolts securing the power steering pump to the mounting bracket. 14 Slacken the adjusting bolt locknut and turn the adjusting bolt until ail the tension Is removed from the dnvebelt. 15 Undo the bolts and remove the pulley guard from the power steering pump then slip the drivebelt off the pulleys,
16.10b Removing the drivebelt from the alternator pulley
18 Ensuring that the correct type of dnveberti^ used, fit the belt around the pulleys and turn
the
adjusting bolt to just take up the slack in thi j belt. Adjust the tension correctly as described! below. Air conditioning compressor drivebelt 17 Slacken the bolts securing the adjustment j pulley bracket to the engine. 18 Slacken the adjusting bolt locknut and] turn the adjusting bolt until ell the tension is | removed from the drivebelt. then slip the be& | off the pulleys. 19 Ensuring that the correct type of drivebeX; is used, fit ihe belt around the pulleys and turn | the adjusting bolt to just take up the slack
m
] the belt. Adjust the tension correctly as described below.
Tensioning 20 Correct tensioning of the belt will ensure that it has a long life. A belt which is too slack will slip and perhaps squeal. Beware, however, of overiightenlng. as this can cause wear in the alternator, power steering pump or air conditioning compressor bearings. Note: Flat recommend use of their spec's/ tensioning tool however the following procedure will set the tension correctly. 21 The belt(s) should be tensioned so that, under firm thumb pressure, there is approximately 5.0 mm of free movement at the mid-point between the pulleys. To adjust, tighten or loosen the relevant adjustment bolt until the tension is correct. Fully tighten the pivot and adjustment lockbotts. Repeat this procedure for any remaining drivebeits removed for access. 22 Refit the lower timing belt cover end tighten the mounting bolts. 23 Refit the upper timing belt cover and secure with the clips. 24 Refit the inner cover and wheel, lower the vehicle to the ground, then reconnect the battery negative terminal.
17 Clutch adjustment check
Refer lo Chapter 6, Section 2.

2A*10 SOHC (8-valve) petrol engine in-car repair procedures
2.11 Unscrewing the crankshaft pulley bolts
6 Itae crankshaft sprocket Is also equipped •nth a timing mark - when this is aligned with 3relarence marking on the oil pump cover.
Hie
engine is set with cylinders No 1 and 4 at
TDC.
Note that it is the camshaft positioning that determines whether a cylinder is on its comcression or exhaust stroke.

Location
of TDC on cylinder No 1 7 Remove the air cleaner and ducting as descnbed in Chapter 4A or 4B. Remove the
spark
plug from No 1 cylinder as described in Chapter 1A. 8 Firmly apply the handbrake, then |ack up
the
front of the car and support it securely on iiia stands (see Jacking end vehicle support). 9 Remove the auxiliary drivebelt(s) as described in Chapter 1A. 10 Unbolt and remove the timing belt cover. Mole the bolt located at the bottom of the
coven
this can be easily overlooked. 11 Undo the three bolts and remove the crankshaft pulley from the sprocket (see {lustration). 12 Turn Ihe engine in its normal direction of rotation (using a socket or spanner on Ihe crankshaft sprocket centre bolt) until pressure an be felt at No
1
cylinder spark plug hole.
1 flfliyflg^ Remove all four spark plugs; "••"•1 this will make the engine HlNTl easier to turn; refer to Chapter 1A for details.
13 Continue turning the engine until the crahaft sprocket TDC timing mark is aligned with the mark on the cylinder head and the crankshaft sprocket timing mark is aligned with the mark on the oil pump cover (see ilustrations). 14 The engine is now set at TDC for No 1 cylinder on compression.
3 Cylinder compression test t ^
1 When engine performance Is down, or if misfiring occurs which cannot be attributed to tne ignition or fuei systems, a compression isst can provide diagnostic clues as to the
2.13a Camshaft sprocket and cylinder head TDC timing marks (arrowed) aligned -shown with timing belt removed engine's condition. II the test is performed regularly, it can give warning of trouble any other symptoms become apparent. 2 The engine must be fully warmed-up to normal operating temperature, the battery must be fufly charged, and all the spark plugs must be removed (Chapter 1A). The aid of an assistant will also be required. 3 Disable the ignition system by dis-connecting the LT wiring plug to the ignition coils. 4 Fit a compression tester to the No 1 cyl-inder spark plug hole - the type of tester which screws into the plug thread is to be preferred, 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the highest reading obtained. 6 Repeat the lest on the remaining cylinders, recording the pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates the existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on the first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked head could also be the cause). 8 If the pressure in any cylinder is very low. carry out the following test to isolate the cause. Introduce a teaspoonful of clean oil into that cylinder through its spark plug hole and repeat the test. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear Is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a biown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between them; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower
2.13b Crankshaft sprocket and oil pump cover TDC timing marks (arrowed) aligned
than the others and Ihe engine has a slightly rough idle, a worn camshaft lobe could be the cause. 12 On completion of the test, refit the spark plugs and reconnect the ignition LT wiring plug.
4 Timing belt and covers -removal and refitting ^
Note: Fiat specify the use of a special timing belt fens/on measuring toot to correctly set tho timing belt tension. If access to this equipment cannot be obtained, an approximate setting can be achieved using the method described below. It the method described is used, the tension must be checked using the special tool at the earliest possible opportunity. Do not drive the vehicle over large distances, or use high engine speeds, until the belt tension is known fo be correct. Refer to a Fiat dealer foradvSce.
General information 1 The function of the timing belt is to drive Ihe camshaft and coolant pump. Should the belt slip or break In service, the valve timing will be disturbed and piston-to-valvo contact will occur, resulting in serious engine damage, 2 The timing belt should be renewed ai the specified intervals (see Chapter 1A), or earlier if it is contaminated with oil. or if it is at all noisy in operation (a scraping noise due to uneven wear). 3 If the timing belt is being removed, it Is a wise precaution to check the condition of the coolant pump at the same time (check for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fall.
Removal 4 Firmly apply the handbrake, then jack up the front of the car and support it securely on axle stands (see Jacking and vehicle support). Remove the right-hand front road wheel. 5 Remove the air cleaner and air ducting as described in Chapter 4A or 46. 6 Remove the auxiliary drivebelt(s) and the spark plugs as described in Chapter 1A.
2A

2B*4 DOHC (16-valve) petrol engine in-car repair procedures
4.8 Undo three bolts and romove tho crankshaft pulley from the sprocket
Crankshaft setting toot fabrication 7 To make Ihe crankshafl setting tools, four old spark plugs will be required, together with four lengths of dowel rod. The length of each dowel rod is not critical, bul It must be long enough to protrude about 100 mm above the top of the cylinder head extension when resting on top of a piston located half way down its bore. What is critical, however, is that all four do wo I rods must be exactly the same length. 8 Break off the ceramic upper section of each plug and remove the centre electrode and earth tip. The easiest way to do this is to mount each spark plug in a vice (attar removing the ceramic uppor plug section) and drill a hole down through ihe centre of the plug. The diameter of Ihe drill bit should be the same as Ihe diameter of Ihe dowol rod to be used. When finished you should have four spark plug bodies and four equal length dowel rods which will slide through the centre of the spark plugs.
3 Cylinder compression test
1 When engine performance is down, or it misfiring occurs which cannot be attnbuted to the Ignition or fuel systems, a compression test can provide diagnostic clues as to the engine's condition. If the lest is performed regularly, it can give warning of trouble bofore any other symptoms become apparent.
4.10 Undo the upper timing cover upper retaining bolt, and the rear retaining boll
4.9 Undo the retaining bolt in the centre of the lower timing cover
2 The engine must be fully warmed-up to normal operxrtrfjg temperature, the battery must be fully charged, and all the spark plugs muse be removed (Chapter 1A>. The aid of an assistant wilt also be required. 3 Disable the ignition system by discon-necting the LT wiring plugs to the Ignition coils. 4 Fit a compression tester to the No t cylinder spark plug hole • the type of tester which screws into the plug thread is to be preferred. 5 Have the assistant hold the throttle wide open, and crank the engine on the starter motor; after one or two revolutions, the compression pressure should build up to a maximum figure, and then stabilise. Record the h.ghest reading obtained 6 Repeat the test on the remaining cylinders, recording Ihe pressure in each. 7 All cylinders should produce very similar pressures; any excessive difference indicates Ihe existence of a fault. Note that the compression should build up quickly in a healthy engine; low compression on (he first stroke, followed by gradually increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked head could also be tho cause). 6 If the pressure in any cylinder is very low, carry out the following test to isolate the cause. Introduce a teaspoonful of dean oil into that cylinder through its spark plug hole and repeal the lest. 9 If the addition of oil temporarily improves the compression pressure, this indicates that bore or piston wear is responsible for the pressure loss. No improvement suggests that leaking or burnt valves, or a blown head gasket, may be to blame. 10 A low reading from two adjacent cylinders is almost certainly due to the head gasket having blown between Ihem; the presence of coolant in the engine oil will confirm this. 11 If one cylinder is about 20 percent lower than the others and the engine has a slightly rough idle, a worn camshaft lobe could be the cause. 12 On completion of the test, refit the spark plugs and reconnect the ignition LT wiring plug.
4 Timing belt and covers -removal and refitting §
General information 1 The luncUon of the timing belt Is to drive the camshafts and coolant pump. Should the bell slip or creak in service, the valve timing will be disturbed and piston-to-valve contact wiu occur, resulting in serious engine damage. 2 The timing belt should be renewed at the specified Intervals (see Chapter 1A), or earlier If It is contaminated with oil, or if it is at all noisy In operation (a scraping noise due to uneven wear}. 3 If the timing belt is being removed, it is
a
wise precaution to check the condition of the coolam pump at the same time (oheck for signs of coolant leakage). This may avoid the need to remove the timing belt again at a later stage, should the coolant pump fail. 4 Before carrying out this procedure, it will be necessary to obtain or fabricate suitable camshaft locking tools and piston positioning tools as described in Section 2. The procedures contained In this Section depict the use of the home-made alternative tools described in Section 2. which were fabricated In the Haynes workshop. If the manufacturers tools are being used instead, the procedures are virtually identical. Oo not attempt to remove the timing bell unless the special totfs or their alternatives are available.
Removal 5 Disconnect the battery negative terminal (refer to Disconnecting the battery in the Reference Section of Ihis manual). 6 Remove the auxiliary drivebelt(s) as described In Chapter 1A. 7 Remove the air cleaner, Inlet air duct and resonator as desenbed In Chapter 4B. 8 Undo the three bolts and remove the crankshaft pulley from the sprocket (see illustration). 9 Undo the retaining bolt In the centre of the lower liming cover (see illustration). 10 Undo tho uppor timing cover upper retaining bolt, and the rear retaining bolt located above the alternator (see illustration). 11 Release the crankshaft TDC sensor wiring from the clip on the upper timing cover, then withdraw the cover slightly and slide Ihe wiring plug and socket from the liming cover slot (see illustrations). 12 Release the TDC sensor wiring from the periphery ol the upper and fower timing covers and remove both covers (see Illustrations). 13 Free the accelerator inner cable from the throttle cam, remove the outer cable spring dip, then pull the outer cable out from its mounting bracket rubber grommet. 14 From the side of the throttle body, disconnect the wiring connectors from the

2B*5 DOHC (16-valve) petrol engine in-car repair procedures
4.11a Release the crankshaft TDC sensor wiring from the clip on the upper timing cover... throttle potentiometer and the Idle control stepper motor. Disconnect the coolant temperature sensor wiring connector located
in
the inlet manifold below the throttle body,
end
disconnect the brake servo vacuum hose. 15 Disconnect the wiring connectors for the fuel injector harness and the intake air temperature/pressure sensor, then fcconnect the fuel pressure regulator vacuum hose and the EVAP purge valve hose. 18 Undo the two bolts securing the plastic mlet manifold upper section to the lower section. Release the spark plug HT lead from the location groove in the manifold upper wctton, then lift the upper section, complete
»ith
throttle body, off the engine. Recover the 0-rngs from the manifold ports. 17 Unscrew the two bolts securing the fuel
4£1a Screw the spark plug bodies of the homo-made piston positioning tools into each spark plug hole ...
4.21b ... place a suitable washer or similar into the recess to keep the dowel rod vertical...
4.11b ... then slide the wiring plug and socket from the timing cover slot
rail assembly to the inlet manifold lower section, then carefully pull the Injectors from the manifold. Lift the fuel rail and Injector assembly, with fuel hoses still connected, and position it to one side. 16 Undo the bolts securing the engine management ECU mounting brackets to the body and move the ECU to one side without disconnecting the wiring connector. 19 Remove the spark plugs as described in Chapter 1A. 20 Unscrew the two sealing plugs from the front and rear of the cylinder head extension to enable the camshaft locking tools to be inserted. 21 Screw the spark plug bodies of the home-made piston positioning tools into each spark plug hole and insert the dowel rods into each body. To keep the dowel rods vertical, locate a suitable washer or similar over Ihe rod and into the recess at the top of the spark plug hole. In the photos shown here, an old valve stem oil seal housing was used but anything similar will suffice (see illustrations). 22 Using a socket on the crankshaft sprocket centre bolt, turn the crankshaft in the normal direction of rotation until all four dowel rods are protruding from the top of the cylinder head extension by the same amount. As the engine is turned, two of the rods will move up and two will move down until the position is reached where they are all at the same hoight. The best way to check this is to place a straight edge along the top of the rods and turn the crankshafl very slowly until the
4.21c ... then insert the dowel rods
4.12b ... and lower timing covers
straight edge contacts all four rods (see illustration). 23 When all four rods are at the same height, all the pistons will be at the mid-point of their stroke. Using a screwdriver or similar inserted into the front timing hole in the cylinder head extension, check that the timing slot in the exhaust camshaft is approximately aligned with the liming hole. If the camshaft slot cannot be felt, turn the crankshaft through one complete revolution and realign the dowel rods using the straight edge. Check again for the camshaft slot. Note that although the pistons can be at the mid-point of their stroke twice for each cycle of the engine, the camshaft slots will only be positioned correctly once per cycle. 24 With the pistons correctly set, it should now be possible to screw in the camshaft
4.22 Place a straight edge along the top of the rods and turn the crankshaft until the straight edge contacts ail four rods

2B*7 DOHC (16-valve) petrol engine in-car repair procedures
35 Slacken the tensioner pulley retaining nut and reposition the tensioner to align the
mobile
indicator with the fixed reference mark
on the
pulley face (see illustration). Hold the
pdley in
this position and tighten the retaining
nut to the
specified torque. 36 Turn the crankshaft through a further two complete turns In the normal direction of rotation. Check that the timing is correct by alining Ihe piston positioning tools and
camshaft
locking tools as described previously. 37 When all is correct, remove the setting rri
locking
tools and refit the sealing plugs to 1ft© cylinder head extension, using new 0-
nr^s if
necessary. Tighten the plugs securely. 38 Refit the spark plugs as described in Chapter 1A. 39 Refit Ihe ECU and secure with Ihe mooning bolts. 40
Renew the
injector O-ring seals, smear them Kith
8 little
Vaseline then locate the injectors and tef rail onto the inlet manifold lower section.
Saute Ihe fuel rail
with the two retaining bolts. 41 Relit the inlet manifold upper section using new sealing O-rlngs If necessary and
sectre
with the two bolts. 42 Reconnect the wiring connectors for the tot injector harness and the intake air temp-erature/pressure sensor, then connect the fuel pressure regulator vacuum hose and tha
EVAP
purge valve hose. 43 Reconnect the wiring connectors for the ihrottls potentiometer, idle control stepper motor and coolant temperature sensor. Reconnect the brake servo vacuum hose. 44 Refit and adjust the accelerator cable as described in Chapter 4B. 46 Refit the upper and lower timing belt
covers
together with the TDC sensor wiring. 46 Refit the crankshaft pulley and tighten the
three
retaining bolts securely. 47 Refit the air cleaner. Inlet air duct and resonator as described in Chapter 4B. 48
Refit
tha auxiliary drivebelt(s) as described i/t Chapter 1A, then reconnect the battery
S Timing belt tensioner
and
sprockets -
removal
and refitting

Timing
belt tensioner
Removal I
Remove
the timing belt as described in
Section
4. 1 Completely unscrew the tensioner nut and Wiethe tensioner off the mounting stud-Inspection
3 Wipe
the tensioner clean but do not use Kfrents that may contaminate the bearings.
Spin
the tensioner pulley on its hub by hand.
Sfcfl
movement or excessive freeplay is an rcfceticn of severe wear: the tensioner is not 3 serviceable component, and should be nnewsd.
4.33 Holding the camshaft sprocket with the tool described previously while tightening the sprocket bolt Refitting 4 Slide the tensioner pulley over the mounting stud and fit the securing nut. 5 Refit the timing belt as described in Section 4. Camshaft sprocket Removal 6 Remove the timing belt as described in Section 4. 7 Unscrew the bolt and slide the sprocket from the end of the camshaft. Inspection 8 With the sprocket removed, examine the camshaft oil seal for signs of leaking. If necessary, refer to Section 6 and renew it. 9 Check the sprocket teeth for damage. 10 Wipe clean the sprocket and camshaft mating surfaces. Refitting 11 Locate the sprocket on the end of the camshaft, then refit the retaining boll finger tight only at this stage. 12 Refit the timing belt as described in Section 4.
Crankshaft sprocket Removal 13 Remove the timing bell as described In Section 4. 14 Working beneath the engine, unbolt and remove the flywheel lower cover, then hold the flywheel stationary preferably using a tool which engages the flywheel starter ring
<

Alternatively have an assistant engage a wide-bladed screwdriver with the starter ring gear. 15 Unscrew the crankshaft sprocket retaining bolt and slide the sprocket off the end of the crankshaft. The sprocket may have an integral location key on its inner face, or a separate key which locates In a groove in the crankshaft nose may be fitted. Inspection 16 With the sprocket removed, examine the crankshaft oil seal for signs of leaking. If necessary, refer to Section 7 and renew it. 17 Check the sprocket teeth for damage. 18 Wipe clean the sprocket and crankshaft mating surfaces. Refitting 19 Slide the sprocket onto the crankshaft making sure
11
engages the integral key or separate key, then refit the bolt and washer and tighten the bolt to the specified torque while holding the crankshaft stationary using the method described in paragraph 14. 20 Refit the timing belt as described in Section 4.
6 Camshaft
oil
seal -renewal
1 Remove the timing belt and camshaft sprocket as described in Sections 4 and 5. 2 Punch or drill a small hole in the oil seal. Screw a self-tapping screw into the hole, and pull on the screws with pliers to extract the seal. 3 Clean the seal housing, and polish off any burrs or raised edges, which may have caused the seal to fall in the first place. 4 Lubricate the lips of the new seal with clean engine oil, and drive it into position until It seats on its locating shoulder. Use a suitable tubular drift, such as a socket, which bears only on the hard outer edge of the seal. Take care nof to damage the seal lips during fitting. Note that the Seal lips should face inwards. 5 Refit the camshaft sprocket and timing belt as described in Sections 5 and 4.
7 Crankshaft oil seats -renewal I
4.35 Position the tensioner so that the mobile Indicator (1) is aligned with the fixed reference mark (2)
Front (right-hand side) oil seal 1 The front oil seal is located in the oil pump on the front of the crankshaft. Remove the timing belt as described in Section 4 and the crankshaft sprocket as described in Section 5. 2 Using a hooked Instrument, remove the oil seal from the oil pump casing taking care not to damage the surface of the crankshaft. 3 Clean the seating in the housing and the surface of the crankshaft. To prevent damage to the new oil seal as it is being fitted, wrap some adhesive tape around the end of the crankshaft and lightly oil it.

2C«1
Chapter 2 PartC:
Diesel engine in-car repair procedures
Contents
Auxiliary drivebelts - removal and refitting See Chapter 1B Camshaft cover - removal and refitting 6 Camshaft oil seal - renewal 7 Camshaft - removal and refitting See Chapter 20 Crankshaft oil seats - renewal 8 Cylinder compression test « 3 Cylinder head - dismantling and overhaul See Chapter 20 Cylinder head - removal and refitting 9 Engine mountings - inspection and renewal 11 Engine oil and fitter - renewal See Chapter 18 Engine oil level check See Weekly checks
Degrees of difficulty
Flywheel * removal, inspection and refitting 10 General information 1 Location of TDC on No 1 cylinder 2 Oil cooler - removal and refitting 14 Oil pump and pick-up tube • removal, Inspection and refitting 13 Sump • removal and refitting 12 Timing belt and covers • removal and refitting 4 Timing belt tensioner and sprockets - removal, Inspection and refitting 5 Valve clearance check and adjustment See Chapter 1B

Easy,
suitable for novice
with Irttle
|| experience g^
FaMy
eesy,
suitable ^
forbeglnnerwilti
some experience ^
Falrtydfficult, ^ suitable
for
competent DIYmechanic ^

Difficult, suitable
for & experienced DIY mechanic ^
Very
difficult,
^ suitable
for
expert
DfY
jR or professional ^
Specifications
General Engine code:' 1698 cc non-turbo engine 176.B3.000 1698 cc turbo engine: Up to 1997 t76.A3.00aor176.A5.000 1997 onward 176.A3.000or176.B7.000 •Note: See Vehicle Identification for the location of the code marking on the engine. Bore 82.6 mm Stroke 79.2 mm Compression ratio: Non-turbo engine 20.5:1 Turbo engine 19:1 Firing order 1-3-4-2
No 1
cylinder location Timing belt end of engine Titling belt tension See text
Lubrication system Oi pump type By-rotor driven from front of crankshaft Outer rotor-to-houslng clearance 0.080 to 0.186 mm Axial clearance 0.025 to 0.056 mm
Torque wrench settings Nm ibf ft Camshaft cover 10 7 Camshaft sprocket 11B 87 Crankshaft sprocket centre bolt 190 140 Cylinder head: Stage 1 50 37 Stage 2 100 74 StageS Angle-tighten a furtfier 90" Stage 4 Angle-tighten a further 90° CySnder head front bolts 30 22 Flywheel 142 105
Fuel
injection pump sprocket 49 36 Inlet and exhaust manifolds 25 18 Sump 10 7 Timing belt tensioner and idler 44 32

2C*2 Diesel engine in-car repair procedures
4.4a Unbolt the engine oil dipstick tube...
3 Cylinder compression test
Note: A compression tester specifically designed for diesef engines must be used for this test. 1 When engine performance Is down, or if misfiring occurs, a compression test can provide diagnostic clues as to the engine's condition, If the lest is performed regularly, it can give warning of trouble before any other symptoms become apparent. 2 A compression tester specifically Intended for diesel engines must be used, because of the higher pressures involved. The Ie6ter is connected to an adapler which screws Into the glow plug or injector hole. It is unlikely to be worthwhile buying such a tester for occasional use. but it may be possible to borrow or hire one • if not. have the test performed by a garage. 3 Unless specific instructions to the contrary are supplied with the tester, observe the following points: 9) The battery must bo in a good state of charge, the air titter must be clean, end the engine should be at normal operating temperature. b) AH the in/actors or glow plugs should be removed before starting the lest. If removing the injectors, also remove the flame shield washers, otherwise they may be blown out. c) The stop solenoid must be disconnected.
4.4b ... and remove it from the rubber grommet in the oil pump housing
fo prevent the engine from running or fuel from being discharged. 4 There is no need to hold the accelerator pedal down during the test, because the diesel engine air inlet is not throttled. 5 The cause of poor compression Is less easy to establish on a diesel engine than on a petrol one. The effect of introducing oil into the cylinders (wet testing) Is not conclusive, because there is a risk that the oil will sit in the recess on the piston crown, instead of passing to the rings. However the following can be used as a rough guide to diagnosis. 6 All cylinders should produce very similar pressures; a difference of more than 5 bars between any two cylinders Indicates the existence of a fault. Note that the compression should build up quickly In a healthy engine; low compression on the first stroke, followed by gradually-increasing pressure on successive strokes, indicates worn piston rings. A low compression reading on the first stroke, which does not build up during successive strokes, indicates leaking valves or a blown head gasket (a cracked hoad could also be the cause). 7 A low reading from two adjacent cylinders Is almost certainly due to the head gasket having blown between them: the presence of coolant In the engine oil will confirm this,
Leakdown test 8 A leakdown test measures the rate at which compressed air fed into the cylinder Is lost. It is an alternative to a compression test, and in many ways it is better, since the escaping air provides easy identification of where pressure loss is occurring (piston rings, valves or head gasket). 9 The equipment needed for leakdown testing is unlikely to be available to the home mechanic. If poor compression Is suspected, have the test performed by a suitably-equipped garage.
4 Timing belt and covers -removal
and
refitting
Note: Fiat specify the use of a spec/a/ timing belt tension measuring tool to correctly set the timing belt tension. If access to this equipment cannot be obtained, an approximate setting can be achieved using the method described below. If the method described is used, the tension must be checked using the special tool at the earliest possible opportunity. Do not drive the vehicle over large distances, or use high engine speeds, until the belt fens/on rs known to be correct. Refer to a Fiat dealer for advice.
General Information 1 The function of the timing belt is to drive the camshaft and fuel injection pump. Should the belt slip or break in service, the valve timing will be disturbed and piston-to-valve contact
will occur, resulting In serious engine damage. 2 The timing bolt should be renewed at the specified intervals (see Chapter 1B), or earlier If It is contaminated with oil. or If It is at al noisy In operation (a scraping noise due to uneven wear),
Removal 3 Set the engine at TDC on No 1 cylinder
as
described in Section 2. 4 Unbolt and remove tho engine oil dipstick tube and remove It from the rubber gromme! in the oil pump housing (see illustrations), 5 Before removing the timing belt check rts tension by turning the belt through 90" with finger and thumb midway between u* injection pump and camshaft sprockets. This will give you an Idea of the tension to apply when refitting, assuming the tension is already correct. Also note the position of the tensions pulley as a reference mark. 6 Release tho nut on the timing bea tensioner, move the tensioner pulley away from the belt and retlghten the nut to hold the pulley in the retracted position. 7 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 belt off the camshaft, crankshaft and injection pump sprockets, and the idler and tensioner pulleys. Caution: If the belt appears to be In good condition and can be re-used, it fs essential that It Is refitted the same
wsy
round, otherwise accelerated wear will result, leading fo premature failure. 8 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 doutt about its condition. If the engine is undergoing an overhaul, renew the belt as a matter of course, regardless of its apparent conditio*. The cost of a new belt Is nothing compa/ed with the cost of repairs, should the belt freak in service. If signs of oil contamination art found, trace the source of the oil leak and rectify It. Wash down the engine timing baft area and all related components, to remove
sd
traces of oil.
Refitting 9 Before refitting, thoroughly clean the tknmg belt sprockets. Check that the tensioner and idler pulleys rotate freely, without any sign ol roughness. If necessary, renew them as described in Section 5. 10 Ensure that the crankshaft, camshaft and injection pump sprockets are still at their TDC positions as described In Section 2. 11 Engage the timing belt with the crankshaft sprocket, then locate it around the idler pufiey and onto the Injection pump sprocket making sure that it is kept taught. Continue to locate! around the camshaft sprocket and finally around Ihe tensioner pulley (see Illustration) Ensure the belt teeth seat correctly on Ihe sprockets.

Diesel engine in-car repair procedures
2C*11

C«/ffor>: Where applicable observe the drnctbn of rotation markings on the belt. 12 Tension the timing belt by turning the eccentrically-mounted tensioner clockwise: two ities are provided in the side of the tensioner ftb for this purpose - a pair of sturdy right-ircfed circiip pliers can be used to do this or iftemaiively two bolts and a long screwdriver
may be
used. Fiat use a special tensioner tool
located in
the hotos - this consists of a calibrated rod
and
weight. The weight is positioned 60 mm tog the rod to provide the correct tension to the belt, then the tensioner nul is tightened. Tgttn tho tensioner nut to the specified torque
(see
illustrations) 13
If the
tensioner tool Is not available, test the wsicn by grasping the timing belt between the li^er and thumb midway between the camshaft and injection pump pulleys, and Using il through 90" (see paragraph S).
Caution: The above procedure serves only as a rough guide to setting the belt tension. The tension must be checked accurately by a Fiat dealer using the spec/a/ fens/oner tool, at the earliest opportunity. 14 Tum the engine two complete turns clockwise, check that all the timing marks are still aligned then recheck the timing belt tension. If necessary carry out the tensioning procedure again, 15 Refit the components disturbed for access, using the reverse of the removal procedure and bearing In mind the following points: a) Tighten all nuts and bolts to the specified torque, where given. b) Refit the auxiliary dnvebelt(s) as described in Chapter 18.
5 Timing belt tensioner ^ and sprockets - removal, ^ inspection and refitting ^
1 Follow the procedure for removing the timing belt In Section 4, however it is not necessary to completely remove the belt from the timing sprockets provided it is kept fully engaged with them. 2 Unscrew the nut and slide the tensioner off the mounting stud (see illustrations).
Inspection 3 Wipe the tensioner clean but do not use solvents that may contaminate the bearings. Spin the tensioner pulley on its hub by hand. Stiff movemeni or excessive freeplay Is an Indication of severe wean the tensioner is not a serviceable component, and should be renewed, Refitting 4 Slide the tensioner pulley over the mounting stud and screw on the nut. 5 Refer to Section 4 and refit the timing belt.
Timing belt idler pulley
Removal 6 Remove Ihe timing belt as described In Section 4. 7 Unscrew the mounting bolt and remove the idler pulley from the front of the cylinder block (see illustration). Inspection 8 Wipe the idler clean but do not use solvents that may contaminate the bearings. Spin the idler pulley on Its hub by hand. Stiff movement or excessive freeplay Is an Indication of severe wear; the Idler is not a serviceable component, and should be renewed. Refitting 9 Refit the idler to the front of the block and tighten the bolt to the specified torque (see illustration). 10 Refer to Section 4 and refit the liming belt.
Timing belt tensioner
Removal
5.9 Tightening the idler pulley mounting bolt