SAFARI

97 4 DLT ENGINE Engine Wastegate Fig. 164 This feature in turbocharger consists of a bypass valve built into turbine housing. Some part of the exhaust gas going to the turbine is bypassed through this valve. T his is as shown in the sketch. The wastegate arrangement reduces the high boost pressure developed by the compressor to the desired value, thus obtaining the optimum engine performance with controlled peak cylinder pressure. Intercooler : Intercooler is air to air heat exchanger used to cool compressed air from turbocharger prior to entry to inlet manifold. This increases the density of air entering the engine inlet manifold and helps in improving the engine power output, fuel efficiency and emissions. Boost control device (FIP LDA) D uring sudden acceleration, there is a time lag for the turbocharger to supply air into the intake manifold at the desired pressure sufficient for proper combustion, causing heavy black smoke till the turbocharger attains the desired speed and delivers air at the required pressure. To overcome this, a boost control device (LDA unit) is incorporated in the fuel injection pump which is actuated by the air pressure inside the inlet manifold and controls the fuel delivery in accordance with the air pressure available inside the inlet manifold. Maintenance of the turbocharger As there is no mechanical drive connection between engine and the turbocharger, apart from the engine inspection at regular intervals no additional or particular maintenance services are required for the turbocharger unit. Therefore no adjustments or repairs should be carried out on the turbocharger. In case of doubtful performance or difficulties experienced, insist on repair from the authorised Tata Motors Service centre how ever, following precautionarymeasures should be taken to obtain trouble free performance. 1. D uring regular engine inspection look care fully for any oil leakage at the oil inlet banjo connection on the turbocharger bearing housing. Do not run engine unless leakage at this point is rectified. 2. D o not stop the engine suddenly as it may damage turbocharger rotor bearings. Allow engine to idle for some time before switching it off. Similarly, do not race engine suddenly and unnecessarily. 3. S ince the speed of the turbocharger rotor assembly is tremendously high, it must get clean filtered oil which comes from the engine lubrication system.Therefore, Air Suction Compressor Exhaust Turbine Engine Compressor Turbine Exhaust Waste Gate From Air Filter To Exhaust Pipe To Engine Intercooler Cool Air Fig. 187 Fig. 186 ensure cleanliness of the engine oil by adhering to regular schedules of engine oil and oil filter cartridge change intervals given in the service book. 4. A s the unfiltered dust particles coming in the turbocharger compressor may prove dangerous, make sure that there is no leakage in air intake system and that the air filter element is in good condition and sealed perfectly. Repair of turbocharger We do not recommend servicing of turbocharger fitted on this engine. Hence whenever turbocharger is not functioning efficiently it is recommended to replace it with new one.