Hello everyone, so recently I have been working on my 2006 sti, rough lol. So it overheated from a leak in my radiator. I ordered new radiator with fans and all its a nice yonaka high power radiator also did the thermostat. It seemed to fix the overheating problem for a week or so and today I was driving and it just started to rise, wasn't getting on it or anything. It then fell down slowly and soon began to rise again. The fans turn on and my motor was freshly rebuilt heads, new gaskets, new water pump, timing, all that fun stuff. Its 400whp on e85. 20g turbo fmic 850cc injectors intake and some misc mods. I burped the coolant for a solid 30minutes. The temp gauge needle maxed the gauge a couple times but didn't seem to be getting to warm. Since the thermostat, radiator, fans, and water pump were replaced im not sure what else it could be. The car doesn't leak any coolant either and I've checked the radiator multiple times and its still full. Any help is great thanks!!