Ok so my water had a leaky seal so I replaced it, while the pump was out I also replaced the coolant temperature sensor and the other coolant sensor that is in the driver side head (I noticed it was cracked, the sensor not the head, after my header install.) I fill up the coolant correctly so I know there are no air bubbles.

Now that the new sensors are in I have noticed my temperature gauge in my car to run a little more hot/accurate I guess

Normal driving my temp is (roughly judging by my dash needle) around 185-195 which I know is fine. before, with the old sensors, driving around it would be near the "1/4 mark" and the cooling fans would turn on almost right at the 210 middle mark, well I know that was not right knowing that the fans turn on around 230* ish.

The part that freaks me out is now in traffic jam conditions and long stops my temperature starts shooting up much higher than it did before. Now I havent overheated or anything but im still concerned. It starts to creep up near the "3/4 mark" on the temp gauge. I havent been sitting idle long enough to have the fans turn on but it still makes me think my fans might not be working, I just have no idea with these new sensors when the fans should kick on.

Which brings me to my question, at what location on your temp gauge does your fans start kicking on? if its past the "3/4 mark" near the red I guess im fine, I just want to know how high the needle goes before I should worry.



Cliff notes: New coolant sensors, realize how inaccurate the old sensors were, have no idea how near redline in the temperature gauge gets before the fans turn on.

 

honestly, it does sound like you have some air in the system still. Run the car and bleed it some more. i believe fans should turn on around 226ish. so thats pretty close to the 3/4 mark on the gauge.

 

what are some symptoms of having air still in the system, I thought that when the temperature is fine when driving there is no air pockets causing problems,

i could be wrong tho

 

well did you bleed the air out of the coolant once you filled everything back up and got it running again? used the bleeder screws? air pockets will cause the car to run hot.

 

OK, fill the overflow tank, run the engine, then (when the thing is at operating temp) open the two bleeder valves until coolant exits each, then close each valve.

It's that easy!



Yep, you are mistaken; what you described (wide temp variations) is the main symptom of air in the coolant system.

 

ah I opened up the bleeder screws when the car was off, guess I should have done it when it was up to operating temperature, ill get that done today.

 

get the car up to temp, open up one of the screws for like 3 seconds and close. wait 10-15 seconds. open it again. repeat for the other one. do it a few times to each one

 

I bled the cooling system out, there was a small amount of air. I watched the temperature gauge, it got close to the "3/4" mark then it started to fall back down when the fan kicked back on. So i know everything is working just right. I would have been worried if the needle just kept rising but it diddnt. It was just doing its normal cooling cycle.

thanks for the help

 

MY 97 LT1 is doing the same thing. The temp gauge rises a little over the 210 middle mark and at the traffic light almost 3/4's of the way...kinda cutting it close. But when I'm driving goes either just under the half way mark or even down to 1/4s of the way. Why is there such a temperature difference at different driving points?

 

The faster you drive the more airflow over the radiator/engine. Very simple.

 

Gotcha. That idle at the light thing scares the hell out of me. Too close for comfort. I may consider that 180' t stat or something for a piece of mind.

 

Unless you are moving or the fans are on, there is no air flow across the radiator. It's gonna heat up. Your car came stock with a 180° thermostat.