TM 5-2420-230-24-2
B3.9 and B5.9 Series Engines
Lubricating Oil Contamination (007-044)
Section 7 - Lubricating Oil System - Group 07
Page 7-31
Shut off the engine. Wait approximately 5 minutes to let the
oil drain from the upper parts of the engine.
Check the oil level again.
Add oil as necessary to bring the oil level to the "H" (high)
mark on the dipstick.
Lubricating Oil Contamination
(007-044)
General Information
Lubricating Oil Dilution
CAUTION
Diluted oil can cause severe engine damage.
Check the condition of the lubricating oil.
Thin, black lubricating oil is an indication of fuel in
the oil.
Milky discoloration is an indication of coolant in the
lubricating oil.
Coolant in the oil can be caused by:
Expansion plugs leaking
Lubricating oil cooler element leaking
Damaged cylinder head or gasket
Cracked engine block
Casting porosity.
Coolant-Diluted Lubricating Oil
Since the lubricating oil cooler design does not require
gaskets or seals to maintain the separation of oil and cool-
ant, the element itself must leak to allow mixing of the
fluids. Refer to Procedure 007-003.
L-1043
