Hey guys.... So i drive mostly highway on my way home from work. And today it was pretty hot so i turned my a/c on. While im crusing i notice my temp gauge going up and up. so i turn the a/c off, goes back to normal, then i turn it back on temp goes up. Idk why its doing it. so when i got home i looked under the hood. the coolant resivior was over flowin so it was all being pushed out of the block. idk if thats what its suppose to do when it over heats or not. But im im just curious as to why its doing this. any help would be great!

 

Mine would do that untill i took the radiator out and cleaned it. It was plugged full of dirt, weeds, and bugs. when the temp goes up the antifreeze expands so it will technicaly look like there is more in there and could cause it to come out of the resivior.

 

i'm just throwing this out there so please don't just do what i say.

have you changed the thermostat recently? maybe it was put in backwards. i don't know why i posted that. it just kinda came to mind that your a/c and overheating is the opposite of what should happen when it starts to overheat.

 

the thermostat is open already wayyyyy before it starts to overheat. once your temp gauge starts to go up from the bottom, the thermostat is open. if it was put in backwards the truck would overheat quickly. within 10 minutes.

 

1 take a hose with light sprayer for say flowers and rinse your radiator out. Rinse both sides.


2 take the radiator cap off and let your truck warm up for about 10 minutes with the heat on high. Top off the radiator and replace the cap. This will work out any air in the system.


3 replace your radiator cap, it might be shot.



Im willing to bet you were low on coolant and created a pocket of steam in your engine. Check the level of the radiator once a week just to make sure your not leaking.

 

thermostat hasnt been replaced..

coolant level is good. last time i flushed her out was about 3 years ago so maybe she needs a good flushin up front.