What is considered HOT in terms of temperature to suggest a blown head gasket?

Last week drove a 97 Deville with AC on and at highway speeds and also start stop and it showed a temp of 212 on the display. The outside air was only about 51 so I have no idea what the temp would be in 90 or 100 degree air which we generally have in the summer in MD.

My C5 Corvette with the LS1 engine ran at a max of 189 degrees under the same conditions. Was the Deville exhibiting overheating in this cold air environment.

What do you consider NORMAL for the temp in this weather?

BIGHANK

 

Prolonged operating temp over 235 on open highway. Normally should stay under 220 even on hot days. I would suggest to flush cooling system if there is any doubt of its condition. In town if cooling fans can't control engine temp

 

driving around, that sucker can go as high as 234... but on the highway, it should stay closer to 200 210.... I have noticwd by reading threads that all caddy's run different temps... that is just ahigh but still a good range..
Alex