Engine Warm-Up - Peterbilt 348 2017 Operator's Manual

CAUTION
Always unplug heater before starting
the engine. Damage to the cooling
system could occur if the heater is
not turned OFF (unplugged).
Depending on engine make, when the
temperature falls below -10° F (-24°
C), the block heater is required.
•
Use a solution of half ethylene
glycol antifreeze and half water for
best heater performance. Do not
exceed 65 percent concentration
of antifreeze, as a shortened
heater life will result. See Engine
Cooling System on page 5-80, for
more information.
•
After servicing the cooling system,
operate the vehicle for a day or two
before using the heater. Trapped
air inside the engine needs time
to escape.
(03/17)

Engine Warm-up

Engine
The purpose of engine warm-up is to
allow oil film to be established between
pistons and liners, shafts and bearings
while your engine gradually reaches
operating temperature.
Warm-up Procedure
1. After you've started your engine,
idle it at approximately 600 RPM
while you check:
a. oil pressure
b. air pressure
c. alternator output
2. After a few minutes of idling at
600 RPM, increase your idle
speed to 900 or 1000 RPM.
Continue your warm-up. This
procedure allows oil to warm and
flow freely while pistons, liners,
shafts, and bearings expand
Y53-6060-1C1
STARTING & OPERATING
slowly and evenly. In extremely
cold temperatures, you may have
to increase idle speed.
NOTE
In colder climates where the tem-
perature is often below freezing,
the warm-up for turbocharged en-
gines is especially important. Chilled
external oil lines leading to the tur-
bocharger will slow the oil flow until
the oil warms, reducing oil available
for the bearings. Watch the engine
oil temperature or pressure gauge
for a warming trend before increas-
ing engine idle speed (RPM).
3. Continue the engine warm-up until
the coolant temperature reaches
at least 130° F (54° C). At this
temperature, you can use partial
throttle. Wait until the coolant
temperature is at least 160° F (71°
C) before operating at full throttle.
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