I notice that sometimes at idle, my temp gauge goes up. As soon as i start moving, the gauge goes down. I find it strange. At first I believed that the thermostat was the culprit, but if that was the case, the problem wouldn't occur only at idle. Highway driving is not a problem. Can someone give me some advice? Oh incase u need to know, its a 92 H23A1, but i doubt that matters.

 

falty sensor perhaps? I would check that out and make shure the temp sensor isnt faulty, you dont have any coolant leaks right?

 

Nah no coolant leaks. I had thought it was the temp sensor and its funny u said that bcuz that was one of the first things i was gonna check 2morrow. Thanks!

 

np G good luck

 

First try bleeding out your coolant system. Then try the thermostat.

 

Sounds like your fans arent coming on. Make sure they are. When you are stopped, you have no airflow across the radiator. Once you start moving, air flows through the radiator cooling the car down.

neil

 

Your radiator fan is out. The same thing happened to me.

 

Yea, you prob have air in your coolant system. There should be a little bleeder valve/stem right on top of your thermostat housing ( its small, like a 10mm).

Turn your car on and make sure your heater core (head switch) is open and open the little nipple and dont close it until you get a steady stream of green commin out. IF you have air it will kinda sputter a little. Be patient w/it b/c it may take the air a min or so to get to the nipple.

 

The bleeder bolt is a 12mm.

I'm saying the fan is not turning on... I would definietely bleed the system anyways and throw in a new thermostat and radiator cap. Or if you are tight on money, start with the fans and work your way from there.

 

yeah thanks guys but i should have mentioned that i had this problem b4. My fans r always on b/c i jumped them. this solved the problem for a while, but now its back and i have bled the coolant system b4. i never thought about the cap but it seems like it still hold the pressure. ill post what happens w/ new thermostat.

 

I'm not trying to make fun, or anything like that but not everyone is as mechanically inclined as others. So, you have a car with the fans runing all the time, over heats only at idle. Ok, I have to ask the obvious stuff. The mixture is mixed to X % water and X % coolant? not just coolant only right? anything less than 50% water unless its freezing where you live is not enough. Ok, assuming that is good, check to make sure the thermostat is opening. You can check this by feeling the upper coolant hose. It will be hot when the thermostat opens. If thats good, how old is the thermostat? Is it the right opening temperature? How old is the radiator? any mods on the motor that might contribute to the problem, like underdrive pullies? shoot us some info and we'll see if we cant solve the problem for you.

Neil

 

i think i fixed my problem by changing my thermostat and my temperature switch. fans work properly and temp gauge doesnt skyrocket! Thanks guys for all ur help!

 

i had a very similar problem:

it used to only happen when i had the lights and windshield wipers on, that if i sat still, the temp guage would just rocket toward overheating, so i figured that under too much draw, the fans werent coming on.....wrong, they were....

recently, on hot days, if i idled for more than about two minutes, the guage would go up a bar, most of the time i could crank the heat and it would go back down, but often it would keep going up and i would shut the car off....but then as soon as i put the key back in and started it up, the temp guage was normal...

now i thought it was either the guage or the sensor, but both appear to be ok.....

so i analyzed the coolant, given that it was somewhat warm when i did it, and it told me i was at perfect 50/50, but the thing reads a little off unless the coolant is completely cold....so i start squeezing the radiator hoses and adding as much water as i can get in, and i end up adding a bunch....every time i gave a quick squeeze to the upper hose, and a few times on the lower, huge air bubbles would come up....

also, i could hear the thermostat moving when i did that, so maybe it was stuck earlier and i forced it open and now its functioning again.....either way i havent had the problem since....