Chapter 1 Routine maintenance and servicing

1595Ford Fiesta Remake2D•18 Engine removal and overhaul procedures11.14 Using feeler gauge blades to removepiston rings12 After removal, reassemble the big-endbearing caps and shells on their respectiveconnecting rods, and refit the bolts fingertight.Leaving the old shells in place untilreassembly will help prevent the bearingrecesses from being accidentally nicked orgouged. New shells should be used onreassembly.Inspection13 Before the inspection process can begin,the piston/connecting rod assemblies mustbe cleaned, and the original piston ringsremoved from the pistons.14 Carefully expand the old rings over the topof the pistons. The use of two or three old feelerblades will be helpful in preventing the ringsdropping into empty grooves (see illustration).Be careful not to scratch the piston with theends of the ring. The rings are brittle, and willsnap if they are spread too far. They are alsovery sharp - protect your hands and fingers.Note that the third ring may incorporate anexpander. Always remove the rings from the topof the piston. Keep each set of rings with itspiston if the old rings are to be re-used.15 Scrape away all traces of carbon from thetop of the piston. A hand-held wire brush (or apiece of fine emery cloth) can be used, oncethe majority of the deposits have beenscraped away.16 Remove the carbon from the ring groovesin the piston using an old ring. Break the ringin half to do this (be careful not to cut yourfingers - piston rings are sharp). Be careful toremove only the carbon deposits - do notremove any metal, and do not nick or scratchthe sides of the ring grooves.17 Once the deposits have been removed,clean the piston/connecting rod assemblywith paraffin or a suitable solvent, and drythoroughly. Make sure that the oil return holesin the ring grooves are clear.18 If the pistons and cylinder liners/bores arenot damaged or worn excessively, the originalpistons can be refitted. Normal piston wearshows up as even vertical wear on the pistonthrust surfaces, and slight looseness of thetop ring in its groove. New piston rings shouldalways be used when the engine isreassembled.11.24 Check that the connecting rodoilway on CVH engines is clear19 Carefully inspect each piston for cracksaround the skirt, around the gudgeon pinholes, and at the piston ring “lands” (betweenthe ring grooves).20 Look for scoring and scuffing on thepiston skirt, holes in the piston crown, andburned areas at the edge of the crown. If theskirt is scored or scuffed, the engine mayhave been suffering from overheating, and/orabnormal combustion which causedexcessively high operating temperatures. Thecooling and lubrication systems should bechecked thoroughly. Scorch marks on thesides of the pistons show that blow-by hasoccurred. A hole in the piston crown, orburned areas at the edge of the piston crown,indicates that abnormal combustion (preignition,knocking, or detonation) has beenoccurring. If any of the above problems exist,the causes must be investigated andcorrected, or the damage will occur again.The causes may include incorrect ignitiontiming, or a carburettor or fuel injectionsystem fault.21 Corrosion of the piston, in the form ofpitting, indicates that coolant has beenleaking into the combustion chamber and/orthe crankcase. Again, the cause must becorrected, or the problem may persist in therebuilt engine.22 Check the piston-to-rod clearance bytwisting the piston and rod in oppositedirections. Any noticeable play indicatesexcessive wear, which must be corrected. Thepiston/connecting rod assemblies should betaken to a Ford dealer or enginereconditioning specialist to have the pistons,gudgeon pins and rods checked, and newcomponents fitted as required.23 Don’t attempt to separate the pistonsfrom the connecting rods (even if non-genuinereplacements are found elsewhere). This is atask for a Ford dealer or similar enginereconditioning specialist, due to the specialheating equipment, press, mandrels andsupports required to do the job. If thepiston/connecting rod assemblies do requirethis sort of work, have the connecting rodschecked for bend and twist, since only suchengine repair specialists will have the facilitiesfor this purpose.12.1 Checking crankshaft endfloat with adial gauge24 Check the connecting rods for cracks andother damage. Also on CVH engines, checkthat the oilway in the base of the connectingrod is clear by probing with a piece of wire(see illustration). Temporarily remove thebig-end bearing caps and the old bearingshells, wipe clean the rod and cap bearingrecesses, and inspect them for nicks, gougesand scratches. After checking the rods,replace the old shells, slip the caps into place,and tighten the bolts finger-tight.12 Crankshaft -removal and inspection4RemovalNote: The crankshaft can be removed onlyafter the engine has been removed from thevehicle. It is assumed that the transmission,flywheel/driveplate, timing belt/chain, cylinderhead, sump, oil pump pick-up/strainer, oilbaffle, oil pump, and piston/connecting rodassemblies, have already been removed. Thecrankshaft left-hand oil seal carrier/housingmust be unbolted from the cylinderblock/crankcase before proceeding withcrankshaft removal.1 Before the crankshaft is removed, checkthe endfloat. Mount a DTI (Dial Test Indicator,or dial gauge) with the stem in line with thecrankshaft and just touching the crankshaft(see illustration).2 Push the crankshaft fully away from thegauge, and zero it. Next, lever the crankshafttowards the gauge as far as possible, andcheck the reading obtained. The distance thatthe crankshaft moved is its endfloat; if it isgreater than specified, check the crankshaftthrust surfaces for wear. If no wear is evident,new thrustwashers should correct theendfloat.3 If no dial gauge is available, feeler gaugescan be used. Gently lever or push thecrankshaft all the way towards the right-handend of the engine. Slip feeler gauges betweenthe crankshaft and the main bearingincorporating the thrustwashers to determinethe clearance.