I have replaced the radiator with a ford racing aluminum 2 row radiator. I switched to a 185 t-stat. I just put in a haydenheavy dutyfan clutch. I am running 80% water 20% antifreeze, with a bottle of watter wetter. Sometime before i purchased the car (about a year ago)the waterpump was replaced, it doesn't make any noise nor does it leak. Anytime i am driving the car stays very cool, but anytime i am at an idle, the temperature will continue to rise until i either start driving again, or shut it off and let it cool down.

What could be my problem? Head gasket or head bolt, or maybe my water pump?

thanks in advance for all help

 

mine does that too. one (hot) day i left my AC off and it stayed cool.. well a little warm but closer to the usual temp.
of course when you are idling, there's not nearly as much air blowing over the radiator, so the hot air doesn't get moved out. but i'm not sure how to avoid overheating at idle.
maybe an electric fan?

 

"BBK u/d pullies"

I noticed this in your sig...

 

yea i now got a feeling its my underdrive pulley too. im gonna let it get to a good operating temp and then put it in neutral and hold my rpms up at about 1k and see if it'll keep rising. I think that will tell me if its the pulley or not. What do you think?

 

a little higher. about 1800 will be a good spot to test. if it works, its either the pulley, or the system isn't full/has air

 

could have some air pockets in the system... but i have ud pullies 2 and mine dosnt like traffic at all... but when u cruizeing there is no problem so could just be the pullies..

 

it could also be your blades for your water pump (i know this may be way off but hey you never really know.) they may have rusted out and dissolved. there is an easy check. make sure your car is cool not too hot or you might burn yourself ( might need to be at operating temp because of the thermastat ). firmly squeeze the upper radiator hose while accelerating the car from the throttle body. if the hose is surging then your water pump is fine and you can get that thought out of your head. takes what maybe 2min always worth a shot to check.