CESSNA AIRCRAFT COMPANY FOR TRAINING USE ONLY
MODEL 152 7-15
Oil temperature is indicated by a gage located on the subpanel. 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 38°C (100°F) to 118°C
(245°F), and the maximum (red line) which is 118°C (245°F).
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.
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.
The airplane is delivered from the factory with corrosion preventive oil in the engine. If, during the first
25 hours, oil must be added, use only aviation grade straight mineral oil conforming to Specification No.
MIL-L-6082.
ENGINE OIL SYSTEM
Oil for engine lubrication is supplied from a sump on the bottom of the engine. The capacity of the
engine sump is six quarts (one additional quart is required if a full flow oil filter is installed). Oil is drawn
from the sump through an oil suction strainer screen into the engine-driven oil pump. From the pump,
oil is routed to a bypass valve. If the oil is cold, the bypass valve allows the oil to bypass the oil cooler
and go directly from the pump to the oil pressure screen (full flow oil filter, if installed). If the oil is hot,
the bypass valve routes the oil out of the accessory housing and into a flexible hose leading to the oil
cooler on the front side of the left forward engine baffle. Pressure oil from the cooler returns to the
accessory housing where it passes through the pressure strainer screen (full flow oil filter, if installed).
The filter oil then enters a pressure relief valve which regulates engine oil pressure by allowing excessive
oil to return to the sump, while the balance of the pressure oil is circulated to various engine parts for
lubrication. Residual oil is returned to the sump by gravity flow.
An oil filter cap/oil dipstick is located at the rear of the engine on the right side. The filler cap/dipstick is
accessible through an access door in the engine cowling. The engine should not be operated on less
than four quarts of oil. To minimize loss of oil through the breather, fill to five quarts for normal flights
of less than three hours. For extended flight, fill to six quarts (dipstick indication only). For engine oil
grade and specifications, refer to Section 8 of this handbook.
An oil quick-drain valve is available to replace the drain plug in the oil sump drain port, and provides
quicker, cleaner draining of the engine oil. To drain the oil with this valve installed, slip a hose over the
end of the valve and push upward on the end of the valve until it snaps into the open position. Spring
clips will hold the valve open. After draining, use a suitable tool to snap the valve into the extended
(closed) position and remove the drain hose.
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