Mitsubishi S12R-Y1PTA, Operation & Maintenance Manual

Page: 51 / 96

5-4
Chapter 5 ENGINE OIL
Service limits of engine oil
Engine oil degrades through the use and by lapse of time.
To determine the timing of engine oil replacement, analyze the used oil, and understand the condition of oil deterio-
ration and oil defacement. It is also required to compare the oil analysis results and the engine analysis results
including inside contamination and wear condition of engine, and to consider the engine operating condition.
The engine oil affects the engine oil quality to use, the engine operating condition and the quality of fuel. Analyze
the used oil, and understand the condition of oil deterioration and oil defacement. To determine the timing of engine
oil replacement, the stabiration of engine is required.
Refer to the following table for the determination of engine oil performance degradation. If any of the following devi-
ate the limit, replace the engine oil with new oil.
Engine oil analysis service
For a long term service life of engine, it is recommended to get an engine oil analysis service.
It is a system to understand the availability of the engine oil using in your engine by sampling it with the special sam-
pling tools.
The engine oil analysis service provides the followings:
Œ
The quantity of fine metal powder in engine oil due to abrasion, by which worn parts can be located.
Œ
Water, LLC or salt that should not be in engine oil can be detected.
Œ
Engine oil deteriorating conditions, by which appropriate engine oil renewal intervals, operating conditions, proper
inspection and maintenance schedule can be planned.
The engine oil analysis service can diagnose the internal condition of the engine, which is necessary when disas-
sembling the engine. It is highly recommended to take advantage of our engine oil analysis service so that you can
learn the engine condition before any malfunction occurs to the engine.
Table 5-1 Engine oil properties
Properties Standard Test method
Kinetic viscosity
mm
2
/s [in
2
/s]
@100°C [212 °F]
+3.0 % or less change of new oil
10 mm
2
/s [0.155 in
2
/s] or more
JIS K 2283
:2007
ISO 3107
ISO 2909
+30 % or less change of new oil
-20 % change of new oil
Total base number mgKOH/g
2.0 or more with hydrochloric acid
(HCL) method
1/2 of new oil or more with perchlo-
ric acid (PCA) method
JIS K 2501
:2003
ISO 3771
Total acid number mgKOH/g Up to +3.0 of new oil
JIS K 2501
:2003
ISO 3771
Water content Vol % 0.2 or less
JIS K 2275
:1996
ISO 9029
Flash point (open cup) °C 180 or higher
JIS K 2265
:2007
ISO 3769
ISO 2719
Pentane insoluble Wt % 0.5 or less ASTM D 893
Pentane insoluble coag-
ulated
Wt % 3.0 or less ASTM D 893