CESSNA SECTION 7
MODEL 152 AIRPLANE & SYSTEMS
DESCRIPTIONS
1 July 1978 7-16
ENGINE INSTRUMENTS
Engine operation is monitored by the following instruments: oil pressure gage, oil temperature
gage, and a tachometer.
The oil pressure gage, located on the left switch and control panel, is operated by oil pressure.
A direct pressure oil line from the engine delivers oil at engine operating pressure to the oil
pressure gage. Gage markings indicate that minimum idling pressure is 25 PSI (red line), the
normal operating range is 60 to 90 PSI (green arc), and maximum pressure is 100 PSI (red
line).
Oil temperature is indicated by a gage located on the left switch and control panel. The gage
is operated by an electrical-resistance type temperature sensor which receives power from the
airplane electrical system. Oil temperature limitations are the normal operating range (green
arc) which is IOO°F (38°C) to 245°F (118°C), and the maximum (red line) which is 245°F
(118°C).
The engine-driven mechanical tachometer is located near the upper center portion of the
instrument panel. The instrument is calibrated in increments of 100 RPM and indicates both
engine and propeller speed. An hour meter below the center of the tachometer dial records
elapsed engine time in hours and tenths. Instrument markings include a normal operating
range (green arc) of 1900 to 2550 RPM, and a maximum (red line) of 2550 RPM. The upper
end of the green arc is "stepped" to indicate approximate RPM for 75% engine power at sea
level (2350 RPM), at 4000 feet (2450 RPM), and at 8000 feet (2550 RPM).
NEW ENGINE BREAK-IN AND OPERATION
The engine underwent a run-in at the factory and is ready for the full range of use. It is,
however, suggested that cruising be accomplished at 65% to 75% power until a total of 50
hours has accumulated or oil consumption has stabilized. This will ensure proper seating of
the rings.
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