Cirrus SR22 User manual

CIRRUS AIRPLANE MAINTENANCE MANUAL MODEL SR22
79-00
Page 1
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EFFECTIVITY:
OIL
1. GENERAL
This chapter covers those units and components external to the engine concerned with storing and deliver-
ing lubricating oil to and from the engine. These items include the oil filter, oil cooler, oil filler cap/dipstick,
oil pressure/temperature gage, oil pressure sensor, and oil temperature sensor. Refer to the manufac-
turer’s approved Instructions For Continued Airworthiness and/or other service instructions.
The oil supply is contained in a wet sump attached to the bottom of the crankcase. A conventional dipstick
integral to the oil filler cap is provided for determining oil quantity.
When the crankshaft is turning, oil is drawn through a screen and pick up tube which extends from the
sump to a port in the crankcase. Oil then passes to the inlet of the gear-type, engine-driven oil pump and is
forced under pressure through the pump outlet. A pressure relief valve prevents excessive oil pressure by
allowing excess oil to be returned to the sump. After exiting the pump, the pressurized oil enters a full-flow
filter and is passed on to the oil cooler. If the filter element becomes blocked, a bypass relief valve will open
to permit unfiltered oil to flow to the engine. As the oil enters the oil cooler, an oil temperature control unit
directs the flow in one of two directions; when the oil is cold, the oil temperature control unit opens and
bypasses most the oil around the cooler, as the oil warms, the oil temperature control unit closes off the
cooler bypass and forces the oil through the cooler core. In operation, the oil temperature control unit mod-
ulates to maintain oil temperature in the normal range of approximately 170° F.
After leaving the cooler, the oil enters the crankcase where various channels and passageways direct it to
the bearing surfaces and other areas requiring lubrication and cooling such as the valve lifters, inner
domes and lower cylinder walls. Oil within the engine gravity drains back into the sump.
15 Apr 2007

79-00
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EFFECTIVITY:
CIRRUS AIRPLANE MAINTENANCE MANUAL MODEL SR22
15 Apr 2007
2. TROUBLESHOOTING
Trouble Probable Cause Remedy
High oil temperature indication. Thermostat damaged or held
open by solid matter.
Remove, clean valve and seat. If
still inoperative, replace.
Oil viscosity too high. Drain and refill with correct sea-
sonal oil grade. (Refer to 12-10)
Prolonged ground operation. Limit ground operation to a mini-
mum.
Malfunctioning gage or bulb unit. Check wiring. Check bulb unit.
Check gage. Replace malfunction-
ing parts.
High power, low airspeed. Adjust power - flight altitude.
Low oil supply. Replenish oil supply.
Cooler air passages clogged. Clean cooler thoroughly.
Cooler core plugged. Remove cooler and flush thor-
oughly.
Baffle damaged. Inspect baffling for damage or
worn seals. Replace as required.
Fuel system set too lean. Adjust mixture setting in accor-
dance with the manufacturer’s
approved Instructions For Contin-
ued Airworthiness and/or other
service instructions.
Low oil pressure indication. Low oil supply. Replenish oil supply. (Refer to 12-
10)
Oil viscosity too low. Drain and refill with correct sea-
sonal oil grade. (Refer to 12-10)
Foam in oil due to presence of
alkaline solids in system.
Drain and refill with fresh oil. (It
may be necessary to flush cooler
core if presence of alkaline solids
is due to previous cleaning with
alkaline materials.) (Refer to 12-
10)
Pump producing low pressure. Replace pump.
Malfunctioning pressure gage. Check gage. Replace if required.
Weak or broken oil pressure relief
valve spring.
Replace spring. Adjust pressure to
30-60 psi with oil at normal operat-
ing temperature.