6.4.5. Walk-around check and servicing As the condition of turbocharger depends greatly on how well the engine is serviced, it is very important to maintain the engine in accordance with the specified maintenance procedure. 1) Intake system Pay particular attention to the air cleaner when servicing the intake system. In the case of wet-type air cleaner, if the level of oil surface is lower than specified, cleaning effect is poor; if too high, the cleaner draws in oil to foul the case. Especially, if the rotor is fouled, the sophisticatedly-tuned balance is broken to create vibra- tion and to cause seizure and unusual wear to the bearing.
Therefore, it is very important to use a good quality air cleaner all the time. In the case of dry-type air cleaner, it is essential to clean it to reduce intake resistance as much as possible. 2) Exhaust system Pay particular attention to prevent gas leaks and seizure when servicing the exhaust sys- tem because leakage of exhaust gas from discharge pipes, turbocharger fixing portions, etc. lowers charging effect. As such components as turbine chamber that becomes red-hot during operation use heat resisting steel nuts, do not interchange these nuts with ordinary steel nuts. In addition, apply anti-seizure coating to fixing nuts on the portions as designated.
3) Fuel system If the full load stopper regulating the maximum injection volume and the maximum speed stopper regulating the maximum speed in the fuel injection pump are adjusted without using a pump tester, the turbocharger rotates at excessively rapid speed and may suffer damage. Besides of it, if spray pattern from the fuel injection nozzles is bad or the injection timing is incorrect, temperature of exhaust gas rises up to affect the turbocharger adversely. To avoid such trouble, be sure to make a nozzle test. 4) Lubricating system Pay particular attention to oil quality and oil filter change intervals when servicing the lubri- cating system.
Deteriorated engine oil affects adversely not only the engine but torso the tur- bocharger. Suggested engine oils for the turbocharger-mounted engine are as follows : * If long oil change intervals are to be used, ACEA-E3 oil must be used. - 165 - MAINTENANCE OF MAJOR COMPONENTS Engine model Recommend oil SAE No. API No. DE12T/TI/TIA SAE 15W40 above CD or CE DE12TIS SAE 15W40 SAE 10W40 ACEA-E2 or ACEA-E3 (API CH-4)