help...mysterious ka-t overheating

[bboyer]

my ka24det is overheating and i cant figure out why. I blew my headgasket bc my radiator blew and overheated the motor a few weeks ago. I decided to rebuild my t25 replace my rad with an aluminum one and installed a cometic headgasket. now after everything is in and i got it started it starts to overheat after it has been on idle for about 30-45 min. the motor is smooth and my a/f ratio is right on...

I thought i might have damaged my thermostat so i replaced it. and it still does the same thing. it gets to normal operating temp and around half an hr on idle the temp creeps up. i removed my waterpump and checked it...seems to be working perfectly..im almost out of ideas. if anyone can help me out it would be great. any suggestions or tests that i can do to troubleshoot this problem is appreciated. thanks

[iambape]

do you hear the thermostat open?

got electric fans?

[jesse5150]

Did you bleed your cooling system? And you can tell if your thermostat is opening by feeling the upper hose, if it is really hot and stiff and your lower hose is cool and doesnt have pressure your thermostat is not opening. You can also put it into a bowl of HOT water and see if it opens. ALSO you can check your water pump by taking off your radiator cap and reving your engine and see if the coolant is flowing. I hope this helps a little, however I've had more than a few experiences with KA's and the cooling system not being completely bled.