Turbocharger - Diesel: Operation

Turbine impeller of turbocharger is driven by exhaust gases expelled from cylinder combustion chambers. At idle, no pressurization of intake air takes place and engine operates like a normally aspirated engine.

With engine under partial load, throttle valve opens, speed and volume of exhaust gases increase, which turns turbine impeller at a higher RPM. Increased RPM of compressor impeller boosts pressure of intake air. With engine under full load, exhaust gases are at maximum pressure, which increases RPM of turbine and compressor impellers. With engine under full load, exhaust gases are at maximum pressure and increase RPM of turbine and compressor impellers.

After engine has been started, it should be run at idle for several minutes. If engine has been shut down for a long period, engine should be run at idle until oil circulates throughout the system. When turbocharger has been replaced with a new unit, it should be lubricated by removing oil pipe, loosening flare nut and pouring fresh engine oil directly through oil filler port.

During operation, oil pressure should be monitored to confirm that normal oil pressure is constantly available. If hitting or rumbling noise is produced by rotating parts of turbocharger or unusual vibration is noted, stop engine and inspect system.

At stopping, before turning engine off, allow to idle for several minutes. If an engine, operated at high load, is stopped abruptly, turbocharger bearings will overheat and could become damaged. If an engine oil supply is cut off while turbocharger is still hot causing overheated and damaged turbocharger bearings.