TROUBLESHOOTING THE HMMWV - OD1616 - LESSON 1/TASK 1
to operate. If the temperature is above 40 F, then heavy duty engine
oil (OE/HDO 30) is used. If the temperature ranges between 40 F to
-15 F, then OE/HDO 10 oil is used, And, if the temperature falls
between -15 F to -65 F, an arctic-type engine oil (OEA) must be
used.
The engine lubrication system is composed of an oil pan reservoir,
oil filter, gear-driven oil pump, and an oil cooler.
The pump is
mounted on the rear main bearing cap. The oil is picked up by a tube
and is pumped to the oil cooler. The oil cooler is mounted in front
of the radiator. The oil then flows from the oil cooler to the oil
filter, which is located on the left side of the engine.
The oil
filter is of the cartridge type, and all oil going to the engine must
first pass though the filter. This type of filter is also called a
full flow filter.
The engine is equipped with a spring-loaded bypass valve. This valve
protects the engine from oil starvation by opening when the filter
becomes restricted.
From the oil filter, the oil passes on to the
engine block. There is an oil sensing unit located on the left rear
of the cylinder block, which senses the pressure of the oil in the
left main gallery.
This sending unit is connected to the oil
pressure gage, located on the instrument panel.
The gage registers
the signal sent from the sending unit and indicates to the driver if
the pressure of the lubrication system is above, at, or below its
normal operating range.
g.
Engine Electrical System.
The electrical system for the 6.2
liter diesel engine is a 24 volt system capable of submerged
operation during fording.
The engine electrical system is composed
of the starter, alternator, glow plugs, glow plug controller,
protective control box, and the wiring harness.
Operation of the engine electrical system will be discussed in task
two of this lesson, since this system is also a part of the vehicle
electrical system.
h.
Exhaust System.
The waste products of combustion are carried
from the engine to the rear of the vehicle by the exhaust system,
where they are expelled to the atmosphere. The exhaust system
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