Dodge D350 1990 - Malfunctioning Turbocharger; Oil Consumption and Leaks

Exhaust System and Intake Manifold
DODGE Turbo Diesei
Air System
Page 11-5
Malfunctioning Turbocharger
Failure of the internal components of the turbocharger can
reduce its effectiveness and also cause excess smoke and low
power. A bearing failure can produce friction which will slow
the speed of the rotor assembly. Failed bearings can also allow
the blades of the rotor assembly to rub the housings, thus
reducing the rotor assembly speed.
Oil Consumption and Leaks
Engine lubricating oil is used to lubricate the bearings and
provide some cooling for the turbocharger. The oil is supplied
to the turbocharger through the supply line at engine operating
pressure. A return line connected to the bottom of the
turbocharger routes the oil back to the engine oil pan.
Seals are used on each end of the rotor assembly. The primary
function of the seals is to prevent exhaust gases and
compressed air from entering the turbocharger housing. Oil
leakage from the seals is rare, but it can occur.
A restricted or damaged oil return line will cause the
turbocharger housing to be pressurized causing oil to migrate
by the seals.