Navistar WorkStar Series, Operator'S Manual

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Operation
The lubricating oil in a diesel engine becomes dark in color
after short periods of engine operation. This discoloration is not
harmful to engine parts as long as the oil and oil filter element
changes are performed at recommended intervals.
Engine Performance Problems
• Low engine power can be the result of a plugged fuel filter.
Fuel filters can plug prematurely due to the use of fuel that
is contaminated with a high amount of sediment, microbial
growth, or water.
Fuel that has been stored for longer
periods of time may also reduce engine performance.
• Failure to maintain the vehicle as required in the
Maintenance
Instructions and Maintenance Intervals
and Specifications sections of this manual, as well as any
separately available Engine Operation and Maintenance
Manual, can cause engine performance problems.
Too low of cetane number could cause hard starting and
slower warmup and could increase engine noise and exhaust
emissions.
Fuel
Ultra Low Sulfur Diesel Fuel Requirements
Ultra Low Sulfur Diesel (ULSD) fuel is required for all on-highway
diesel engines used with advanced after-treatment systems
(Diesel Particulate Filters – DPF). For complete details on fuel
requirements, see the Engine Operation and Maintenance
Manual supplied with the vehicle.
Unacceptable Fuel Blends
Biodiesel blends having more than 5 percent pure biodiesel are
not within ASTM D975 diesel specifications.
To determine acceptable biodiesel and biodiesel blends, refer to
the Engine Operator and Maintenance Manual for the applicable
engine.
Hazards of Diesel Fuel/Gasoline Blends
WARNING
Never add gasoline, gasohol and/or alcohol to
diesel fuel.
This mixture creates an extreme
fire and explosion hazard which could result in
property damage, personal injury, or death.
Blending of gasoline and/or alcohol with diesel fuel is not
recommended due to the hazards of fire/explosion and the
detrimental effects on engine performance.
As little as two percent volume gasoline mixed with diesel fuel
will create a flammable/explosive mixture in the fuel tank vapor
space, which will pose an extreme fire/explosion hazard during
refueling or engine operation.
Additional Unsafe Practices
CAUTION
To prevent engine damage, do not mix propane
with diesel fuel.
Warranty claims will not be
honored against engines that have used propane.
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