What is oil analysis?  Is it important?

HIGHLY RECOMMENDED  The chemical analysis of the crankcase oil of a gasoline or diesel
motor speaks volumes about problems in that motor.  The presence of metals indicates wear,
antifreeze or water can indicate blown head gaskets or cracked blocks or heads.  Fuel in the
oil can indicate misfiring cylinders.  It is the best place to start as to whether an engine survey
is justified.  Note: Fuels and lubricants can also be analyzed.  (2cycle outboards cannot have
oil analysis as they do not have oil sumps).
From the Surveyor's Notebook