Operating Instructions Operating the Engine
Medium Duty
(R10/06) Y53-6008 – 63 –
After the engine starts and until operating conditions reach a
certain point, the system will continue to operate to eliminate
white-smoke exhaust.
Engine Warm–Up and Idling
The purpose of engine warm-up is to allow an oil film to be
established between pistons, shafts, and bearings while your
engine gradually reaches operating temperature.
Warm–Up Procedure
1. After you have started the engine, idle the engine at
approximately 600 rpm while you check vital engine sys-
tems:
– oil pressure
– air pressure
– alternator output (with the optional voltmeter)
2. Before placing engine under a load, continue warm-up
with the engine at 900 to 1000 rpm for 3 to 5 minutes.
• When a cold engine is started, increase the engine
speed (rpm) slowly to be sure adequate lubrication
is available to the bearings and to allow the oil pres-
sure to stabilize. In extremely cold temperatures,
you may have to increase idle speed.
NOTE: In colder climates where the tempera-
tures are often below freezing, sufficient warm-
up for turbocharged engines is especially impor-
tant. 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 pressure gauge for a
warming trend before increasing engine idle
speed (rpm).
3. Continue the engine warm-up until the coolant tempera-
ture reaches at least 130°F (54°C). At this temperature,
you can use partial throttle. Wait until the coolant temper-
ature is at least 160°F (71°C) before operating at full
throttle. See “
Operating Manual Transmissions” on page
67.
WARNING! Exhaust fumes from the engine con-
tain carbon monoxide, a colorless and odorless
gas. A poorly maintained, damaged, or corroded
exhaust system can allow carbon monoxide to
enter the cab or sleeper. Failure to properly
maintain your vehicle could cause carbon mon-
oxide to enter the cab and cause serious ill-
nesses.
