freightliner 114SD - Engine Oil Pressure Gauge; Engine Oil Temperature Gauge

Under heavy loads, such as when climbing steep
grades, temperatures that exceed the normal oil tem-
perature range for a short period are not unusual. If
the temperature returns to normal when the load de-
creases, there is no problem.
Engine Oil Pressure Gauge
NOTICE
A sudden decrease or absence of oil pressure
may indicate mechanical failure. Bring the vehicle
to a safe stop and investigate the cause to pre-
vent further damage. Do not operate the engine
until the cause has been determined and cor-
rected.
The engine oil pressure gauge, as shown in
Fig. 4.9,
displays the current engine oil pressure. If engine oil
pressure falls below the minimum levels shown in
Table 4.4, the CHECK engine lamp will illuminate. If
the condition does not improve, the STOP engine
lamp will also illuminate and an audible warning will
sound. The engine will then derate or shut down, de-
pending on the type of engine protection system
installed.
Minimum Oil Pressure
*
Engine Model
At Idle Speed:
psi (kPa)
At Rated RPM:
psi (kPa)
Caterpillar 10–20 (69–138) 30–45 (207–310)
Cummins 15 (103) 35 (241)
Detroit 14 (97) 55 (350)
Mercedes-Benz 7 (50) 36 (250)
*
Oil pressures are given with the engine at operating temperature. With
the engine cold, oil pressure may be higher. Individual engines may vary
from the listed pressures; observe and record pressures when the engine
is new to create a guide for checking engine condition.
Table 4.4, Minimum Oil Pressure
Engine Oil Temperature Gauge
NOTICE
A sudden increase in oil temperature that is not
caused by a load increase may indicate mechani-
cal failure. Bring the vehicle to a safe stop and
investigate the cause to prevent further damage.
Do not operate the engine until the cause has
been determined and corrected.
During normal operation, the optional engine oil tem-
perature gauge (
Fig. 4.10) should read in the follow-
ing temperature ranges:
•
160 to 195°F (71 to 91°C) for Caterpillar en-
gines
•
200 to 260°F (93 to 126°C) for Detroit and
Cummins engines
•
177 to 203°F (81 to 95°C) for Mercedes-Benz
engines
FWD
150 250
300100
°F
04/19/2013 f611205
Fig. 4.8, Forward-Rear Drive Axle Oil Temperature
Gauge
10/09/2001
0
100
50
PSI
OIL
f610528
Fig. 4.9, Engine Oil Pressure Gauge
Instruments
4.10