ok for some reason my car gets a lot hotter at night then during the day...during the day i can run the **** out of my car and it always stays well below the half way mark, then at night i even think of driving hard and she is ata about the 2/3 mark!! i dont know whats up, i ordered a new t-stat so far and plan on installing it as soon as it gets herre, but if anyone has had this problem and could give me some more ideas advise whatever...anything will help

 

oh its a stock 81

 

Well, the only difference I can think of that would matter between day/night driving would be the use of the headlights. This would add strain to the alternator, making it slightly more difficult to turn. The alternator belt also turns the water pump. So, maybe when the alternator tightens up under the load, the belt starts slipping a bit which slows down the water pump and causes overheating....

 

I would also check the sending unit... Sometimes those things have a mind of their own- I would take a guage and put it on it at night and see what it comes up with... You can pick up those lazer thermoters (spelling) at walmart CHEAP... Just see what kind of temps your getting to see if it is "really" getting hot- You might be getting a combination of the alt and strain on the system- causing the guage to read wrong.... If you want to test it for a couple days...go get a mechanical guage and in stall it... Thats what I would dooooo! Good luck!

 

Let us know what fixes the problem. Sounds really weird!

 

thanks for the advice, ill let you guys know what it is as soon as i get it fixed!!!

 

my FB does the samething ...i have done ghetto testing on this.......and this is my ghetto finding....i ran the car during the day and she would be way below the middle temp mark....at night would be a diff story....at night it would raise above the middle mark (like you were stating onslaught 81)....so i tried this during the day....i ran the car with the headlights on during the day and she would go above the middle temp mark just like at night....then immediately after that i would run the car with the lights off then she would go back down below the middle temp mark. So yes its the alternator/belts.....i want to install an FC alt with 80 amps (those just bolt on with out modification) and i need to replace my belts soon......so i think this is your problem...but this has already been stated previously....i just wanted to post the words ghetto testing........