we are having trouble with overheating on my friends turbo s2k. i thought it might just be an airbubble...so we topped off the radiator and let it idle with the cap off for a while. Typically you would expect it to bubble and over flow a little bit... but on his s2k it was shooting about 3-6 in. in the air. I kept trying to fill but it would shoot it all back out within 10 sec. this went on for about 20 min. and i finally gave up. Could the thermostat cause this? There are no leaks anywhere. Its only 70 degrees here....it should not be overheating at idle. Fans are wired to a switch and work fine.

 

fans wired correctly they should be Pulling air through the radiator. also when the car is ideling with the cap on feel the hoses once its to normal temp. if the top hose is hot and the bottom one is cold means your thermostat is sticking and that can cause it to over heat.

 

S2000 is a hard car to get the airbubbles out of.

Jack the car up in the front as high as you can and rebleed the system, there are also two bleeders you can also crack.

 

check to see if the hg is blown with a combustion leak testing tool

 

the problem ended up being the second blown headgasket in one month. We are pulling the motor today and sending it to inline pro to get built