|Username||Post: Engine Temperature|
"7th Year" Silver Supporting Member
06-06-21 04:30 AM - Post#2821200
The cooling system should basically maintain the coolant temp at the thermostat setting (180F, for example) at forward speed (25 mph, or so). At idle/traffic; add about 10%. But the system should return to 'normal' when forward speed is resumed. Temps look mostly normal under the conditions.
A 50/50 coolant mix at 15 psi does not boil until about 265F.
The GM 'idiot' lights did not start to 'illuminate' until around 235F.
A 180F thermostat is recommended for cast iron cylinder heads; 190F for aluminum.
Ignition timing impacts temps. You may 'cool' a little by checking.
Here's a little reading that may be helpful: