Chapter 1 Routine maintenance and servicing

Zetec engine in-car repair procedures 2C•911.5a Note locating dowels when removing camshaft bearingcaps11.5b Inlet camshaft has lobe for camshaft position sensorand evenly the pressure of the valve springson the caps.5 Withdraw the caps, noting their markingsand the presence of the locating dowels, thenremove the camshafts and withdraw their oilseals. The inlet camshaft can be identified bythe reference lobe for the camshaft positionsensor; therefore, there is no need to mark thecamshafts (see illustrations).6 Obtain sixteen small, clean containers, andnumber them 1 to 16. Using a rubber sucker,withdraw each hydraulic tappet in turn, invertit to prevent oil loss, and place it in itsrespective container, which should then befilled with clean engine oil (see illustrations).Do not interchange the hydraulic tappets, orthe rate of wear will be much increased. Donot allow them to lose oil, or they will take along time to refill on restarting the engine,resulting in incorrect valve clearances.Inspection7 With the camshafts and hydraulic tappetsremoved, check each for signs of obviouswear (scoring, pitting etc) and for ovality, andrenew if necessary.8 Measure the outside diameter of eachtappet (see illustration) - take measurementsat the top and bottom of each tappet, then asecond set at right-angles to the first; if anymeasurement is significantly different from theothers, the tappet is tapered or oval and mustbe renewed. If the necessary equipment isavailable, measure the inside diameter of thecorresponding cylinder head bore. Comparethe measurements obtained to those givenin the Specifications Section of this Chapter; ifthe tappets or the cylinder head bores areexcessively worn, new tappets and/or a newcylinder head will be required.9 If the engine’s valve components havesounded noisy, particularly if the noisepersists after initial start-up from cold, there isreason to suspect a faulty hydraulic tappet.Only a good mechanic experienced in theseengines can tell whether the noise level istypical, or if renewal of one or more of thetappets is warranted. If faulty tappets arediagnosed, and the engine’s service history isunknown, it is always worth trying the effect ofrenewing the engine oil and filter (see Chapter1), using only good-quality engine oil of therecommended viscosity and specification,before going to the expense of renewing anyof the tappets - refer also to the advice inSection 5 of this Chapter.10 Visually examine the camshaft lobes forscore marks, pitting, galling (wear due torubbing) and evidence of overheating (blue,discoloured areas). Look for flaking away ofthe hardened surface layer of each lobe. If anysuch signs are evident, renew the componentconcerned.11 Examine the camshaft bearing journalsand the cylinder head bearing surfaces forsigns of obvious wear or pitting. If any suchsigns are evident, renew the componentconcerned.12 Using a micrometer, measure thediameter of each journal at several points. Ifthe diameter of any one journal is less thanthe specified value, renew the camshaft.13 To check the bearing journal runningclearance, remove the hydraulic tappets, usea suitable solvent and a clean lint-free rag toclean carefully all bearing surfaces, then refitthe camshafts and bearing caps with a strandof Plastigauge across each journal. Tightenthe bearing cap bolts to the specified torquewrench setting (do not rotate the camshafts),then remove the bearing caps and use thescale provided to measure the width of thecompressed strands. Scrape off thePlastigauge with your fingernail or the edge ofa credit card - don’t scratch or nick thejournals or bearing caps.14 If the running clearance of any bearing isfound to be worn to beyond the specifiedservice limits, fit a new camshaft andrepeat the check; if the clearance is stillexcessive, the cylinder head must be renewed.15 To check camshaft endfloat, remove thehydraulic tappets, clean the bearing surfacescarefully, and refit the camshafts and bearing2C11.6a Removing hydraulic tappets11.6b Hydraulic tappets must be stored asdescribed in text11.8 Use a micrometer to measurediameter of hydraulic tappets1595Ford Fiesta Remake