Chapter 1 Routine maintenance and servicing

Exhaust and emission control systems 4E•5d) Refit the remaining parts in the reverseorder of removal. Tighten all fasteners tothe specified torque wrench settingswhere given.e) Where drained, refill the cooling system(see Chapter 1).f) Run the engine, and check for exhaustleaks. Check the coolant level when fullywarmed-up to normal operatingtemperature.4 Catalytic converter - generalinformation and precautionsThe catalytic converter is a reliable andsimple device, which needs no maintenancein itself, but there are some facts of which anowner should be aware if the converter is tofunction properly for its full service life.a) DO NOT use leaded petrol in a vehicleequipped with a catalytic converter - thelead will coat the precious metals,reducing their converting efficiency, andwill eventually destroy the converter.b) Always keep the ignition and fuel systemswell-maintained in accordance with themanufacturer’s schedule (see Chapter 1).c) If the engine develops a misfire, do notdrive the vehicle at all (or at least as littleas possible) until the fault is cured.d) DO NOT push - or tow-start the vehicle -this will soak the catalytic converter inunburned fuel, causing it to overheatwhen the engine does start.e) DO NOT switch off the ignition at highengine speeds, ie do not “blip” thethrottle immediately before switching off.f) DO NOT use fuel or engine oil additives -these may contain substances harmful tothe catalytic converter.g) DO NOT continue to use the vehicle if theengine burns oil to the extent of leaving avisible trail of blue smoke.h) Remember that the catalytic converteroperates at very high temperatures. DONOT, therefore, park the vehicle in dryundergrowth, over long grass or piles ofdead leaves, after a long run.I) Remember that the catalytic converter isFRAGILE. Do not strike it with toolsduring servicing work.j) In some cases, a sulphurous smell (likethat of rotten eggs) may be noticed fromthe exhaust. This is common to manycatalytic converter-equipped vehicles.Once the vehicle has covered a fewthousand miles, the problem shoulddisappear. Low quality fuel with a highsulphur content will exacerbate this effect.k) The catalytic converter used on a wellmaintainedand well-driven vehicle shouldlast for between 50 000 and100 000 miles. If the converter is nolonger effective, it must be renewed.5 Positive crankcaseventilation system - checkingand component renewal2Checking1 Checking procedures for the systemcomponents are included in Chapter 1.Component renewal - allengines except ZetecAir cleaner components2 See Chapter 1.Filter/oil separator and hoses3 All the components relating to the positivecrankcase ventilation system, with theexception of the HCS engine filter/adapterlocated on the underside of the air cleaner,may be removed by simple disconnection andwithdrawal (having noted all connections forsubsequent refitting).4 The refitting of all components is a reversalof the removal procedure, ensuring that theconnections are correctly made.Component renewal - ZetecenginesAir cleaner components5 See Chapter 1.Positive Crankcase Ventilation (PCV)valve6 The valve is plugged into the oil separatoron Zetec engines (see illustration).Depending on the tools available, access tothe valve may be possible once the pulse-airassembly has been removed (see Section 7).If this is not feasible, proceed as outlined inparagraph 7 below.Oil separator7 Remove the exhaust manifold (see Section3). The positive crankcase ventilationvalve can now be unplugged and flushed, orrenewed, as required, as described in Chapter1.8 Unbolt the oil separator from the cylinderblock/crankcase, and withdraw it; remove anddiscard the gasket.9 Flush out or renew the oil separator, asrequired (see Chapter 1).10 Refitting is the reverse of the removalprocedure, but use a new gasket between theoil separator and cylinder block. Refill thecooling system (see Chapter 1). Run theengine, check for exhaust leaks, and checkthe coolant level when it is fully warmed-up.6 Evaporative emissionscontrol system - checking2and component renewalChecking1 Poor idle, stalling and poor driveability canbe caused by an inoperative canister-purgesolenoid valve, a damaged canister, split orcracked hoses, or hoses connected to thewrong fittings. Check the fuel filler cap for adamaged or deformed gasket.5.6 Crankcase emission control system (Zetec engine models)1 Oil separator2 Gasket3 Positive crankcase ventilation (PCV) valve4 Cylinder block/crankcase opening5 Crankcase breather pipe and flexiblehoses4E1595Ford Fiesta Remake