Very true that a single UOA isn't very valuable , except for.checking condition of the oil and arriving at the correct OCI.
But a series of them can be quite useful. Case in point for my '99 Grand Cherokee. This is one of the years the 4.0 suffered from the 0331 porous head casting. UOA showed higher than average wear and coolant. Without having the series of 3 UOAs done I might never have known and ended up on the side of the road, but was able to take action.
Further, aircraft engines are sampled and UOAs performed in commercial applications. This practice has caught many failing internals before they caused an emergency situation, and is required in many cases.
But a series of them can be quite useful. Case in point for my '99 Grand Cherokee. This is one of the years the 4.0 suffered from the 0331 porous head casting. UOA showed higher than average wear and coolant. Without having the series of 3 UOAs done I might never have known and ended up on the side of the road, but was able to take action.
Further, aircraft engines are sampled and UOAs performed in commercial applications. This practice has caught many failing internals before they caused an emergency situation, and is required in many cases.
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