Remember too that the gauge may be accurate and showing 100* C, that's not considered to be too hot although the average American likes to see it at or below 80* C, that's not realistic in summer nor with the AC running ~ Diesels are compression ignition and as such love heat and plenty of it .

I too use the Harbor Freight ($30) infra red temperature gauge, it's very handy and easily spots clogged radiator tubes and dragging brakes, etc., etc.......

*DO* check or add a ground wire to the dash binnacle, it makes the gauges more accurate and the lights brighter .

Use a BROWN wire for grounds, always .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better