freightliner CENTURY CLASS S Driver Manual page 108

Engines and Clutches
6. Fuel cloud point is the temperature at which wax
crystals become visible, which is generally above
the pour point of the fuel. To keep the fuel filter
elements from plugging with wax crystals, the
cloud point should be no higher than the lowest
ambient temperature at which the engine must
start.
Cummins
The two most commonly used terms associated with
preparation of equipment for low-temperature opera-
tion are "winterization" and "arctic specifications."
Winterization of the engine and/or components, so
that starting and operating are possible in the lowest
temperature to be encountered, requires:
•
Proper lubrication with low-temperature lubri-
cating oils.
•
Protection from the low-temperature air. The
metal temperature does not change, but the
rate of heat dissipation is affected.
•
Fuel of the proper grade for the lowest tem-
perature.
•
Heat to raise the engine block and component
temperatures to at least –25°F (–32°C) for
starting in lower temperatures.
•
Electrical equipment capable of operating in
the lowest expected temperature. All switches,
connections, and batteries in the electrical sys-
tem should be inspected and kept in good con-
dition to prevent losses through poor contacts.
Arctic specifications refer to the design of material
and specifications of components necessary for sat-
isfactory engine operation in extremely low tempera-
tures to –65°F (–54°C). Contact the nearest Freight-
liner dealer or Cummins engine dealer, to obtain the
special items required.
CAUTION
"Antileak" antifreezes are not recommended for
use in Cummins engines. Although these anti-
freezes are chemically compatible with DCA
water treatment, the "antileak" agents may clog
the coolant filters.
IMPORTANT: Fuel heaters used on vehicles
with Cummins CELECT Plus engine systems
could cause high fuel temperatures that affect
7.17
engine performance and operation of the elec-
tronic engine controls. If a fuel heater is used,
make sure it has thermostatic controls. If the
fuel heater has a timer, set the timer to activate
only for a limited period of time before the en-
gine starts. Make sure the fuel heater is used
only for starting the engine.
For more information, see the Cummins Operation
and Maintenance Manual .
DDE S60
Preparations made in advance of winter and mainte-
nance performed during the cold months will help to
ensure efficient engine starting and operation.
•
Engine oil thickens as it gets colder, slowing
cranking speed. When cold, multi-grade oil of-
fers less resistance to the cranking effort of the
engine and permits sufficient rpm to be devel-
oped to start the engine. See "How to Select
Lubricating Oil" in the Detroit Diesel Engine
Operator's Guide for specific recommenda-
tions.
•
When an engine equipped with a DDEC sys-
tem is started at temperatures below 25°F
(–4°C), the idle speed automatically increases
to 900 rpm. The injection timing is also ad-
vanced to decrease white smoke. As the en-
gine oil warms up, the idle speed gradually de-
creases. When the oil temperature reaches
122°F (50°C), both the idle speed and the in-
jection timing return to normal.
•
A winterfront may be used to improve cab
heating while idling. At least 25% of the grille
opening should should remain open in sec-
tioned stripes that run perpendicular to the
charge air cooler tube flow direction. This as-
sures even cooling across each tube and re-
duces header-to-tube stress, and possible fail-
ure. Winterfronts should only be used when the
ambient temperature remains below 10°F
(–12°C)
•
During cold weather, the batteries should be
tested more frequently to ensure ample power
for starting. All electrical connections should be
tight and in good condition to prevent losses
through loose or corroded connections.
•
Ethylene glycol base antifreeze is recom-
mended. An inhibitor system is included in this