<That infra red temp gun is kinda 'the way' , or sure a nice non-intrusive
internodes way to see what temp you are really running at.
You'd like o see 180ish degree coolant coming out of the engine>

I'll never forget the first time I saw one years ago. A guy in my group caravaning down to Everybus had one, and on a rest stop he used it on his engine and mine (both late bays). My enngine was running about 15 degrees hotter than his, worried me all the way through the rest of the trip as to why mine was running hotter, LOL.    Jeff