Engine Checks Before Operating - GMC TopKick 2007 Owner's Manual

Engine Checks Before Operating

When you have started your engine, let it run for
20 to 30 seconds before you put a load on the
engine. But do not leave the vehicle while
the engine is running.
Avoid unnecessary idling of diesel engine
equipped vehicles.
If the engine idles too long, the temperature of the
engine coolant will fall below the normal operating
range. Low engine operating temperature
causes several conditions which affect engine
operation and reduce engine life.
The engine should be permitted to go through a
warm-up period. Operate the vehicle at a minimum
of 600 rpm during the warm-up period. During
this period and during operation, the following
observations should be made.
During this warm-up period, check your warning
lights and gages:
•
If oil pressure does not begin to rise within
15 seconds of starting, stop the engine
and find the cause. See Oil Pressure Gage on
page 173 for more information.
•
If the engine coolant temperature gage needle
goes into the hot area on the gage, stop the
engine and find the cause of the overheating.
See Engine Coolant Temperature Gage on
page 171 for more information.
•
If you have air brakes, the dual-needle air
pressure gage should read at least 115 psi
(790 kPa) for both service systems before you
try to move the vehicle. When air pressure is
below 60 psi (420 kPa), the LOW AIR light will
come on and you will hear a tone alarm. See
Brake System Warning Light on page 168 for
more information. If the pressure does not build
up or drops during warm-up, stop the engine
and find the cause before you try to move the
vehicle. Recommended air pressure before
driving is 120 psi (830 kPa). See Air Pressure
Gage on page 181 for more information.
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