well the car started overheating about a half mile from my house after a few high speed highway runs. it got up to about 245 F before i was able to shut it down. i found coolant (about a quart) that came from the overflow resevoir vent tube.
in the process of diagnosing i found no coolant in the exhaust, none in the cylinders or on the spark plugs, none in any of the air charge pipes, just from that vent tube. i let the car sit for about an hour to cool down and checked my rad hoses. the upper one was still rather warm and the lower one was downright cold. this would lead me to believe that my thermostat is stuck closed. does that sound like a possibility?
the car was fine while i was ripping on it and then about three miles of just normal driving and a little bit of coasting i noticed me temp gauge rising. i am so lucky i was close to home so i didn't have to get it towed. i am going to do a leakdown test tonight when i get home from work to make sure its not the headgasket (i pray its not). does anyone have any insight as to what else might have caused this to happen?

 

pressure check and see if the rad cap hold 1.1 bar

check the internal pressure of the cooling system to see if it will hold the pressure/leak.

let's just hope it's just a stat or non-operational cap(which will allow the cooling to boil at lower temp).

during one of the canyon runs, one of the ap1 boiled all the coolant, which turns out he had a front plate in the bumper vent, he put some kinda of mesh over the grille and he used top of the 2nd for most of the run.

 

stuck t stat.. just replace and make sure u get all the air out.. im pretty sure when u drive hard on it.. it stays cool cuz the forces the t stat to open.. since the water pump is pumping faster

 

your turbo right?? hows the turbo coolant lines?

 

i was figuring on it being the t stat. i have the mugen t stat and fan switch, plus samco hoses and arc rad cap on order which should be in early next week. i was gonna do these mods anyway, just sucks it had to happen this way. i think it was my car talking to me as for the turbo coolant lines they are in excellent shape. those hoses are actually the very first thing i checked.

 

shoulda just put in a stock t-stat. stock cooling parts on the s2k are damn near perfect from the factory.

 

well, i finally got the tstat out and its opening just like it should. now i am hoping its just the rad cap not working. there was coolant coming from the overflow bottle and thats it. nothing out the exhaust i.e. no smoke.

 

have you run the car yet? does the coolant from the overflow tank get sucked back into the radiator when it cools down?


do you see little air bubbles bubbling into the overflow tank?

 

yeah, before i took anything apart i let the vehicle run to make sure the fans were coming on, (which they are) and it didn't overheat but took a long while to get up to temp (stock cooling system) and no it did not suck any of the fluid back into the rad when it cooled. and i didn't notice any bubbles into the overflow tank because it is still full of coolant

 

Are you running AEM?