Turbocharger: Description and Operation

Component Location, Part 1:

Component Location, Part 2:

The 7.3L DIT Diesel Engine uses an electronically controlled wastegated GTP38 turbocharger to control the intake manifold pressure. An intake manifold pressure sensor provides readings to the PCM, the PCM compares this reading with the vehicle speed and engine load then sends a signal to the solenoid control valve. The solenoid control valve alters the pressure applied to the wastegate actuator to provide the proper position for the wastegate valve providing the proper boost pressure.

The wastegate turbocharger system components are:
^ turbine housing
^ compressor housing
^ center housing
^ compressor manifold
^ turbocharger pedestal
^ exhaust back pressure valve and control solenoid
^ wastegate valve assembly
^ wastegate actuator
^ solenoid control valve
^ intake manifold pressure sensor
^ PCM (Powertrain Control Module)

Turbocharger I.D. Plate:

The turbocharger can be identified by the turbocharger I.D. plate.

The turbine and compressor wheels are mounted on opposite ends of a common shaft. The wheels are enclosed by two housings, and the common shaft is enclosed by the center housing.

High-velocity engine exhaust gases drive the turbine wheel, which turns the common shaft turning the compressor wheel at speeds up to 130,000 revolutions per minute. Air entering the compressor side of the turbocharger is compressed and delivered to the combustion chambers. This compressed air causes more engine power output, better fuel efficiency and better engine performance at higher altitudes.

The turbocharger is supplied with pressurized oil from the engine's main oil gallery through a passage in the turbocharger pedestal. Oil then drains back through another passage in the turbocharger pedestal into the oil pan. This eliminates the need for external lubrication supply and return lines.

Split ring seals are installed at each end of the common shaft between the shaft bearing and wheel assembly to prevent lubricating oil from entering the turbine or compressor area.

The pressurized oil entering the turbocharger also serves to actuate the exhaust back pressure warm-up system. This system consists of an actuator and a butterfly valve. This system operates only during the cold weather warm-up cycle.