This question is in regard of my other ride. It's an '87 olds cutlass GT with the 3.8SFI. When the car is first run the temp guage will go up to about 265*, then you can see that the stat has opened and from then on the guage will fluctuate normally, between 160 and 200*, as the stat opens and closes. Why question is why does the temp get so high when the car is first started and the motor is cold? Yes, I have replaced the stat and the same thing happens. ECU controlled? thanks.

 

is there an electric fan? does the coolant boil over?

 

3rdgen temp gauges to a 'full sweep test' when the engine is being cranked. (some) Camaros seem to be plagued with the needle sticking at max. durning this test (mine was one of them). I'd assume other GM cars do this as will, my '76 suburban did. I doubt this answers your question correctly tough.

 

Yes, there is an electric fan and it works coming on at about 220*. No the coolant does not boil.

 

I suspect that perhaps the guage sending unit is acting funny. Best way to confirn this is to get a temp probe or some piece to test the coolant temp of the rad. Take off the cap(COLD ENGINE) and stick the measuring device in and wait for the stat to open. Compare the guage to the thermometer. Big difference I would change the guage sender.