Piper Comanche PA-24 Service Manual page 606

PWERCOMANCHESER~CE~AL
7C-69. RecommeDdatioDS for Chaugiug Oil. (Refer to latest revision of Lycoming Service Bulletin No.
480 and Lycoming Service Instruction No. 1014.)
CAlJTION
Do not introduce any trade additive to thc basic lubricant unless
recommended by the engine manufacturer.
a.
Oil Change Intervals.
(1) For engines equipped with full-flow oil filters. change the oil and filter each 50 hOl>rs of engine
operation or every four months. whichever comes first.
(2) For engines relying upon pressure screen filtration alone, change the oil and clean the pressure
and suction screens each 25 hours of engine operation or every four months, whichever comes frrst.
b. Ashless Dispersant (Detergent) Oil.
(1)
With the exception of turbocharged engines, new or newly overhauled engines should be broken
in on straight mineral oil for the first 50 hours of operation, or until oil consumption has stabilized. Lycoming
oil additive
PIN
LW-16702 may be used. Mineral oil must also be used following the replacement of one or
more cylinders until the oil consumption has stabilized. Attempting to break-in normally aspirated engines
with detergent oil may result in high oil consumption as the additives in some of these oils can retard the
break-in of the piston rings and cylinder walls.
(2) All new or newly overhauled turbocharged engines must be broken in and operated only with
ashless dispersant (detergent) oil.
(3) In engines that have been operating on straight mineral oil for several hundred hours, a change to
ashless dispserant oil should be made with a degree of caution, since the cleaning action of some additive oils
will tend to loosen sludge deposits and cause plugged oil passages. When an engine has been operating on
straight mineral oil and is known to be in excessively diny condition, the switch to ashless dispserant oil
should be deferred until after the engine is overhauled.
(4) When changing from straight mineral oil to ash less dispserant oil, the following precautionary
steps should be taken:
(a) Do not add ashless dispserant oil to straight mineral oil. Drain the straight mineral oil from
the engine and fill with ashless dispserant oil.
(b) Do not operate the engine with ash less dispserant oil longer than five hours before the first
oil change.
(c) Check all oil screens for evidence of sludge or plugging. Change oil every ten hours if sludge
conditions are evident. Resume normal oil drain periods after sludge conditions improve.
POWER PLANT
PA·24-260 TURBO
2824
Revised: 8115198