I'll spring the trap. Is a used oil analysis (UOA) cost prohibitive or cheap insurance?
Here are some thoughts.
Assuming all the repair work is done by the dealer, it's well discussed that an engine replacement is about $7000, and a water pump replacement is $2000, a difference of $5000.
A single UOA from blackstone is $28 (unless you buy in bulk). Assuming two oil changes a year for the sake of math, that's $56/year extra per oil change for the analysis. This figure could likely be a little more or less depending your driving habits and if you follow the OLM or time/mileage for oil changes.
If my math is right, for a UOA investment
not to pay back, it would take just over 86 years to spend $5000 on UOAs, suggesting it is more cost effective to have a UOA on each oil change to determine water pump failure.
For example, if it takes 10 years for a pump to fail and failure is determined by observing glycol in the oil, the total cost would be UOA investment and water pump replacment cost, 10*56+2000 = $2560 total cost, which is well under half the cost of replacing the engine. It would be up to the owner if this cost is worth it considering the vehicle depreciation after 10 years.