Another possibility, is he sure it's really overheating,
that the temp sending unit isn't faulty?

Definately overheating. Lost most coolant thru overflow, sprayed over engine.
Major bucking so shut it down. Towed to shop. Replaced thermostat and fan clutch.
Not good enough. My bad comment...had both pressure test and cumbustion test.
Both good. I have 3 nissans with issues and easily forget which had what.


I haven't followed this thread from the start -
- sorry if I'm repeating.
Have you scoured the Xterra forums ?
Sometimes these things are endemic and well known -
- to the _Nissan_ people -
... maybe not so much to your local garage guy ...
Good luck.

https://www.clubxterra.org/search/10...ng&o=relevance

John T.