(Table 55, contd)
5055-17
Engine Oil Viscosity : Low - least severe (1)
The Electronic Control Module (ECM) calculates that the amount of
fuel in the engine oil is high.
If equipped, the warning lamp will come on.
5055-18
Engine Oil Viscosity : Low - moderate severity (2)
The ECM detects that the amount of fuel in the engine oil is very
high.
If equipped, the warning lamp will flash. The engine will be derated.
The engine ECM calculates the amount of fuel in the
engine oil based on the engine operating conditions
and the number of Diesel Particulate Filter (DPF)
active regenerations since the last time the
“
Engine
Oil Life Reset
”
was performed.
Note:
Before continuing with this procedure, ensure
that the engine oil has been changed according to the
maintenance schedule. Refer to Operation and
Maintenance Manual, “Maintenance Interval
Schedule”. If the engine oil has been changed,
ensure that the
“
Engine Oil Life Reset
”
is performed.
Refer to Operation and Maintenance Manual, “Engine
Oil and Filter - Change”.
Measuring Fuel Dilution
Diesel fuel is chemically similar to the lubricants that
are used in diesel engines. A slow fuel leak will blend
the fuel into the oil. Normal operating temperatures
may cause volatile parts of the fuel to vaporize. The
fuel that remains in the oil is less volatile.
A closed cup flash test can be performed in order to
detect fuel dilution. The flash test is designed to
measure the volatile parts of the fuel that are
remaining in the oil. Detecting less volatile fuel is
difficult. The less volatile fuel reduces the accuracy of
the flash test.
Since the flash test does not accurately detect
fuel dilution, do not use the flash test as the only
measure of fuel dilution.
Instead, verify the dilution
by the following methods:
• Gas chromatograph fuel dilution test
• Oil viscosity
The test that uses a gas chromatograph is designed
to measure fuel dilution in crankcase oils. The gas
chromatograph can identify the small chemical
differences between diesel fuel and lubricating oil.
Even though the gas chromatograph provides a more
accurate measure of fuel dilution, always verify the
results with the viscosity test.
A significant level of fuel dilution reduces oil viscosity.
If an unacceptable level of fuel dilution is suspected,
the kinematic viscosity of the oil must be measured.
Fuel dilution that is greater than 10 percent will
usually cause viscosity that is less than the specified
viscosity grade. If the oil is still within the specified
viscosity grade, fuel dilution has not reached an
unacceptable level.
Verifying Fuel Dilution
Always verify fuel dilution by the combination of a
viscosity test and a gas chromatograph test. If the
result is in excess of 10 percent, investigate the
cause.
1.
Obtain an oil test kit. Refer to table
Table 56
Oil Test Kits
Region
Part Number
North America and South
America
29990014
Rest of the world
29990011
2.
Follow the instructions that are supplied with the oil
test kit.
3.
Obtain a sample of the oil from the engine. Refer to
Operation and Maintenance Manual, “Fluid
Recommendations - Engine Oil”.
4.
Complete the form that is included with the oil test
kit.
5.
Send the oil sample for analysis. Follow the
instructions that are included with the oil test kit.
Probable Causes
• Diagnostic codes
• Maintenance interval schedule
• Excessive use of active regeneration (wall flow
DPF only)
• Fuel injector seals
• Fuel injector tip
Recommended Actions
Note:
The procedures have been listed in order of
probability. Complete the procedures in order.
112
UENR0612
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