I was wondering what the normal operating temp for an ICE is? Yesterday I was driving and the temp got as high as 215F according to SG2. On the analog temp gauge in the car it was below the half mark. What temp would you guys consider overheating?
I'd think it varies by the thermostat. Gauges vary also. Mid scale for my car I'm told is about 220. Earlier Saturns had the temp gauge up near the red. Saturn changed the gauges so as to not freak out drivers. My Saturn runs at 181*F with the stock 185*F stat. There are those who put in a 195*F stat to bump up the engine temp for better FE. Something I'm thinking of doing myself in the fall once the 90-100 summer passes.
Cool to normal in my Scion xB is 181-186 and with the grill block I got it to 195 for some really good heat from the heater - the radiator fan comes on at 205-206 degrees and that starts to get too hot. According to Miro at Synlube he DID NOT recommend going to a hotter thermostat than the 180-185 degree one that it comes with. Once you start relying on the PRESSURE in the cooling system all the time to prevent boiling over then you are more likely to get hot spots boiling in the engine and burning something up as well as developing a leak under constant pressure condition. I already have a streak of coolent on the under side of the hood above the belts in a new vehicle.
Now my flat head 6 Rambler American engine really ran well at 195 degrees but that was the recommended thermostat temp and it took adjusting of a new thermostat to make it actually operate at that temperature.
What I have read is the the real danger zone is around 250 degrees F. My Saturn will turn on the fan at 220 degF. I have the 195 degree F thermostat, and I am always running around 190.
However, because of grill blocks and such, I installed a manual radiator fan switch that I use to bring the temp back down to 190 degF in traffic jams and at stoplights. The manual fan switch gives me "peace of mind" for when I am stuck in bad traffic. In practice, I usually flip the switch between 210 and 215 degF and wait until it is back down to 190 degF and/or I am moving again.
Trick to try : This may be counterintuitive, but on Saturns, you can emulate a manual fan switch by turning on the AC. Why? Because in addition to the AC, the Fan comes on to keep the engine from overheating under the additional AC load. This may also be true of your car. In a parking lot, open the hood, turn on the car, leave it in park/neutral with the parking brake on, and turn on the AC. Walk out and look at the engine. If the electric Fan is on, then you have the same ECU/PCM logic. Also, while you are driving, turn on the AC and see if the Water Temperature goes down. If yes, then you have the same logic.