SAFARI

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.

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)

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.

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.

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.

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.

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.