G643 (E) Service Manual Chapter 3. Engine Mechanical System
58
Testing and Adjusting
Adhere to the following warnings when performing
any tests or adjustments while the engine is running.
WARNING
Work carefully around an engine that is running.
Engine parts that are hot, or parts that are
moving, can cause personal injury.
WARNING
Exhaust fumes contain carbon monoxide (CO)
which can cause personal injury or death. Start
and operate the engine in a well ventilated area
only. In an enclosed area, vent the exhaust to
the outside.
Engine Oil
Engine Oil Recommendation
The following oil specifications provide the
guidelines for the selection of commercial products :
Use gasoline engine oil. Recommended API service
classification is class SJ grade.
NOTICE
Failure to follow the oil recommendations can cause
shortened engine life due to carbon deposits or
excessive wear.
Prior to changing oil, select an oil based on the
prevailing daytime temperature in the area in which
the engine is operated. The chart in figure is a guide
to selection the proper crankcase oil.
IMPORTANT
: Oils containing “solid” additives, non-
detergent oils, or low-quality oils are not
recommended for use in G643(E) Engine.
Engine Oil Viscosity Recommendation
NOTE
: In normal case, the recommended engine oil
for G643(E) engine is SAE 10W - 30.
But, if the excessive valve noise occurs up to five
minutes after a cold start and if the maximum
ambient temperature is lower than 10°C (50°F), it is
recommended to change engine oil to SAE 5W - 30
for that application.
Synthetic Oils
Synthetic engine oils are not recommended for use
in G643(E) Engine. Synthetics may offer advantages
in cold-temperature pumpability and high-
temperature oxidation resistance.
However, synthetic oils have not proven to provide
operational or economic benefits over conventional
petroleum-based oils in G643(E) Engine. Their use
does not permit the extension of oil change intervals.
Lubrication System Problems
One of the problems in the list that follows will
generally be an indication of a problem in the
lubrication system for the engine.
•
Too much oil consumption.
•
Low oil pressure.
•
High oil pressure.
•
Too much component wear.
