TM 5-2420-230-24-2
Lubricating Oil System Diagnostics (007-048)
B3.9 and B5.9 Series Engines
Page 7-40
Section 7 - Lubricating Oil System - Group 07
If the lubricating oil cooler element ruptures, the lubricating
oil pressure will force lubricating oil into the coolant system.
Lubricating oil in the coolant should be visible when the
radiator cap is removed.
Refer to Procedure 007-003.
Worn or damaged seals in the turbocharger can also allow
lubricating oil to leak into the air crossover pipe and be
burned in the engine.
The condition can be verified by removing the air crossover
tube or charge air cooler tubing and looking for oil.
Inadequate sealing of the piston rings will result in lubri-
cating oil being blown out the breather tube and/or con-
sumed by the engine. Refer to Procedure 001-047 or
003-018.
Lubricating oil can also be lost through a worn or malfunc-
tioning air compressor. Look for carbon buildup in the air
line from the compressor to the air tank. Also, a failed air
compressor head or head gasket can allow oil to leak into
the coolant or coolant to leak into the oil during hot shut-
down. Refer to Procedure 012-003.
L-1052
