i have a '97 gsr. the only mod i have to the motor is an aem cai and a high flow cat err more like a test pipe. I bought an all aluminum bigger core radiator a couple months ago. At first i was running water w/ water wetter but the temp NEVER came up more then 1/4 of the way up, even at idle and as soon as i moved, it went back down to like 2 lines above c, if that. I flushed the system and put back 50/50 coolant and water and when i'm moving the temp is the same but at idle it goes to 1/2 way. No joke, the fans come on, maybe 2 times a day if i'm driving all day.
I've also noticed my gas mileage went to sh*t, 240 miles to a full tank weather i get on it or not. I did a full tune up as well as changed all my filters and now i'm down to 200 miles per tank. Damnit, what the hell? i'm wondering if the car thinks it's still cold and is dumping fuel, kindof like a choke on carbs. plus it's getting kindof cold around here, between 30's and 50's all week. Any ideas, any help? could i need new o2 sensors? i want my gas mileage back damnit!!!

 

I'd replace the thermostat, I'm willing to bet it's stuck open and overcooling the engine. I'm going through the same problem with my 91. Make sure to spend the extra $5 or so and buy a thermostat FROM THE DEALER, don't skimp out and get the Autozone specials. Mine came out to just under $20.

 

You think 30s-50s is cold? Its in the low low 0s here. LOL last night it was a balmy 4 degrees.
When you fluched your system did you change the thermostat? That could be the cause of all your whoas.

 

0? ha, i atleast like to have 2 #'s in my weather forcast. i'll do that this weekend. it didn't even cross my mind. thank you