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YO-233-B2A Engine Maintenance Manual
TEO-540-A1A Engine Maintenance Manual
It is important to know if this is the initial oil change of a new, rebuilt, or overhauled engine.
Typically, small metallic particles, chips, and chunks on either the oil filter element or oil suction
screen during the first oil change of a new, rebuilt, or overhauled engine, are acceptable. After an
initial break-in period, metal content is likely to decrease rapidly to a level that remains essentially
constant.
However, on subsequent oil changes, an increased quantity of chunks, chips, and/or small metal
particles in the oil can be evidence of engine part wear. This wear can increase over a period of time
until premature loss of form, fit, or function occurs.
NOTICE: If the engine has been operated in dust, sand storms, volcanic ash, wildfires, etc. more
particulates could be found.
Table 3 identifies field tests and guidelines for identifying types of metals as well as possible sources
and the next step in the process.
Table 4 identifies the size and amount of material and the recommended corrective action.
Table 5 identifies specific corrective action for the various findings.
The type of material (Table 3), regardless of quantity, and/or the quantity and size of metallic
particles (Table 4) can help determine the corrective action (Table 5) to be taken.
NOTICE:
Table 3 only applies to engines that use genuine Lycoming Parts.
Guidelines for Identification of Metal Particulates and Chips & Corrective Action
Metals/
Tests & Characteristics
Alloys
Steel or cast
Picked up by magnet or,
iron
will move when a magnet
is placed on the opposite
surface of the filter
element or strainer cloth –
which will prevent chips
from sticking to the
magnet
Bronze
When placed in nitric
acid, turns bright green
Nickel
Not picked up by magnet
Stainless steel
© 2021 Avco Corporation. All Rights Reserved
February 2021
Table 3
Possible Source of
Origin on Lycoming
Engine
Camshaft lobes
Gears
Tappets
Push rods
Rockers
Shafts
Impellers
Piston rings
Cylinder barrels
Connecting rod bushings
Rocker bushings
Crankshaft bearings
Intake valve guide
Piston pin plug
Idler gear bushing
Exhaust flange
V-band coupling
Gasket
Valves
Exhaust components
Valve seats
Oil bypass valve spring
Safety wire
Next Step
Refer to Table 4 for
the quantity and size
of the particles
Refer to Table 4 for
the quantity and size
of the particles
Refer to Table 4 for
the quantity and size
of the particles
Refer to Table 4 for
the quantity and size
of the particles
12-10
Page 67
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