boil some water see when it opens. u sure the raditor is clean, inside and out. might be a good ideal to take it to a raditor place have them rod it out.

 

Positive. lol pulled the radiator out, sprayed water on the outside to remove the fuzzies and stuff that get caught in the gills. Gills are straight and narrow and outside is good in general. The inside of the radiator had great flow throughout. Didn't seem to have any hesitation on the flow from top to bottom with the water flowing through it

 

Did you ever find out what was causing you to over heat when at idle?

I am having similar problems. Flushed radiator twice, replaced the coolant, replaced the thermostat twice because it broke twice. I am thinking I may have air in my lines but not sure.