(1997 Accord LX 5sp non VTEC)
just wondering what is the normal range of fluctuation in operating temperature? So basically, my temp gauge needle likes to drop out occasionally, I know it's the gauge itself because of I tap it with my finger it'll fix itself. Driving down the road today it did it, which got me wondering why it does it. I had the thought that maybe over the years it's sort of dug a little notch where it normally sits, and the engines getting hot causing it to raise and fall out of it's notch knocking it "off track". I I plugged in my scanner and the next time it did it I pulled up my live data. Sitting at a light, it was about 205-206 (it's pretty hot here this time of year) so I kept my eye on it, goin down the road a moment later it dropped down to 189. Kept track of it for the rest of the drive, and my ECT fluctuates between these two temps, give or take. I know "normal" operating temperature is between 190 and 220, so my question is what is a normal amount of fluctuation between idling and cruising? Sorry for the long post lol any help is appreciated.
TL;DR what is the normal amount of fluctuation in ECT for daily driving? How much is too much?

 

That all sounds normal. Running temp is somewhere near 186, this is the thermostat temperature. The higher temperature when sitting is the cooling fan set point. Usually on at 206 and off at 203. Roughly. Some variation based on model of car and how far the sensors have drifted with age.

 

thanks for the reply, I'm aware of the ins and outs of the cooling system, I know the fan kicks on a a certain temp and the thermostat opening, my question was more geared towards the range of temperature I was seeing. Seemed a little excessive too me, but I've got some sort of milder form of PTSD from an overheating event a few years back, so I'm probably overthinking it lol. But thank you for the feedback, if it sounds normal to you that eases my mind