read a post about a driver who sprung a coolant leak and said the engine was "severely" overheated and damaged. had a similar experience about a month ago while pulling a load in east texas. burst a coolant hose coming out of a town on Hwy 84, at night, no shoulder to pull off on. ran the cat for about 20 minutes at 200 degrees, dummy light fading off and on intermittently, until i found a place to pull off and repair the problem. lost about 6 gallons of coolant.

how hot is too hot? what kind of damage does it do to the engine?

 

I would not much worry, about that. A bit hot, but not "overheating"! :wink:

 

Assuming the gauge was reading correctly, 200 degrees is not a problem.

The newer Cat engines in the fleet where I work run up to 210 before the engine fan kicks in.

I thought that was too hot, so I read the Cat literature and sure enough, thats the way it's supposed to operate.

 

The dummy light was on because of the low coolant, not the temperature.