Detroit 60 series

212*

 

I'd say normal, especially summertime.
Fan enaged should drop lower. Need to verify gauge accuracy before going any further.

 

Is the code active? Do you have a check engine light on? If you turned the key on while the coolant temp sensor was unplugged, you'd get this fault.

Where are you running, and how heavy? If your coolant temp doesn't get up to temp, your fan will never come on

 

Flat land no wind, hot summer day, truck stays around 180.

Takes a long hill, warm air, heavy load, and the fan doesn’t turn on until like 215. Way too hot for my liking. I always manually turn the fan on around 200-205

 

The engine fan turn-on temperature setting is a fixed value within the Detroit DDEC ECM programming. Your thermostats do have some control on this as there are thermostats that open/close at different coolant temps. My 1999 Pete (factory 500hp series 60 engine) has always had 195 degree stats. My engine fan comes on around 210-215 degrees per the coolant temp gauge needle. Is it exactly accurate? Probably not. So, all is normal. An older diesel engine block making some heat just adds to the seasoning! LOL

 

At 10,000 rpm I’d expect it to be melting down at 1000 rpm 200 is normal.. as far as temperature jumping around I’d suspect a faulty temp sensor..