Chapter 1 Routine maintenance and servicing

1595Ford Fiesta Remake4C•8 Fuel system - electronic fuel injection engines15.1 Exploded view of the inlet manifold arrangement15 Inlet manifold -removal and refitting 4Note: Refer to the warning note in Section 1before proceeding.Removal1 The inlet manifold is a two-piece assemblycomprising an upper and lower section boltedtogether (see illustration).2 Drain the cooling system with reference toChapter 1.3 Depressurise the fuel system as describedin Section 2.4 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).5 Remove the air inlet components (Section4) and disconnect the accelerator cable fromthe throttle linkage (Section 5).6 Remove the fuel injectors and fuel rail asdescribed in Section 14.7 Noting their locations, disconnect thecoolant, vacuum and breather hoses from themanifold.8 Disconnect the wiring multi-plugs from theengine sensors at the inlet manifold.9 Undo the retaining bolts, and withdraw themanifold from the cylinder head. Note thelocation of the engine lifting bracket and earthlead, where fitted. Remove the gasket.10 With the manifold removed, clean alltraces of the old gasket from the matingsurfaces of the manifold and the cylinderhead.Refitting11 Refitting is the reversal of removal. Use anew gasket, and tighten the retaining bolts tothe specified torque (see illustration).Refit the remainder of the components withreference to the appropriate Chapters of thismanual. Refill the cooling system asdescribed in Chapter 1 on completion.16 Turbocharger - generalinformation and precautionsGeneral information1 A water-cooled turbocharger is used on allTurbo models covered by this manual. Theturbocharger increases the efficiency of theengine by raising the pressure in the inletmanifold above atmospheric pressure.Instead of the air/fuel mixture being simplysucked into the cylinders it is actively forcedin.2 Energy for the operation of theturbocharger comes from the exhaust gas.The gas flows through a specially-shapedhousing (the turbine housing) and in so doingspins the turbine wheel. The turbine wheel isattached to a shaft, at the other end of whichis another vaned wheel known as thecompressor wheel. The compressor wheelspins in its own housing and compresses theinducted air on the way to the inlet manifold.3 After leaving the turbocharger, thecompressed air passes through anintercooler, which is an air-to-air heatexchanger mounted with the radiator. Herethe air gives up heat which it acquired whenbeing compressed. This temperaturereduction improves engine efficiency andreduces the risk of detonation.4 Boost pressure (the pressure in the inletmanifold) is limited by the turbochargerwastegate control, which diverts the exhaustgas away from the turbine wheel in responseto the boost control valve. The valve iscontrolled by the EEC IV engine managementmodule.5 The turbo shaft is pressure-lubricated bymeans of a feed pipe from the engine’s main oilgallery. The shaft “floats” on a cushion of oil. Adrain pipe returns the oil to the sump.6 Water cooling reduces the operatingtemperature of the turbocharger, and inparticular, the shaft bearings. Water continuesto circulate by convection after the engine hasstopped, so cooling the unit if it is hot after along run.Precautions7 The turbocharger operates at extremelyhigh speeds and temperatures. Certainprecautions must be observed to avoidpremature failure of the turbo or injury to theoperator.a) Do not operate the turbo with any partsexposed. Foreign objects falling onto therotating vanes could cause extensivedamage and (if ejected) personal injury.b) Do not race the engine immediately afterstart-up, especially if it is cold. Give the oila few seconds to circulate.c) Always allow the engine to return to idlespeed before switching it off - do not blipthe throttle and switch off, as this willleave the turbo spinning withoutlubrication.d) Allow the engine to idle for severalminutes before switching off after a highspeedrun.e) Observe the recommended intervals foroil and filter changing, and use areputable oil of the specified quality.Neglect of oil changing, or use of inferioroil, can cause carbon formation on theturbo shaft and subsequent failure.17 Intercooler -removal and refitting2Removal1 Disconnect the battery negative (earth) lead(refer to Chapter 5A, Section 1).2 Remove the flexible hose connecting theintercooler to the air inlet duct, then the pipe