Teledyne TSIO-360-RB, Maintenance Manual

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7-5
7-5 SPECTROGRAPHIC OIL ANALYSIS (continued)
A proper spectrographic oil analysis program should begin with the first engine oil change.
Establishing a wear trend data base for an engine will require analysis of at least three oil
samples. As the engine accumulates operating time and additional oil samples are
analyzed, a definitive wear trend can be identified. Unexplained deviations from normal
wear trend patterns should be investigated using accepted, conventional inspection
methods.
Spectrographic oil analysis must be accomplished according to a set protocol to provide any
useful information. Even if done properly, spectrographic oil analysis will rarely provide any
prior indication of a fatigue type failure. A single spectrographic oil sample will usually not
provide a high level of useful information since there is no established wear trend data on
that specific engine for comparison.
Spectrographic oil analysis will assist in the identification of an internal engine problem. If
samples are properly taken at regular intervals, it should provide the owner / operator and oil
analysis technician with information relative to normal or abnormal wear that occurs during
the course of engine operation. Deviations from an established wear trend pattern should
alert the owner / operator and oil analysis technician to further investigate.
Limitations
Variations in operation, use and maintenance may be reflected in the parts per million
content reported. Deviations from standard or previously used sampling procedures may
result in variations to the parts per million content in the sample report.
General Procedures
To establish a data base for comparison and analysis, oil samples must be taken on a
regular schedule using the same sampling techniques and laboratory. The engine must
have been operated long enough to obtain normal operational temperatures and the oil
sample taken within 30 minutes after engine shut down. The tube or funnels used to drain
the oil from the sump must be clean and free of any foreign material or residue. If the oil
sample is taken from the oil as it drains from the sump, allow approximately 1/3 of the oil
drain prior to taking the sample. If the sample is taken via the oil filler or other location using
a sampling tube, it is critical the sample be taken from two or three inches above the bottom
of the oil sump, not from the bottom. Do not take an oil sample from the oil filter canister.