Alright guys im stumped... Ive got a 04 g35 sedan was only overheating on express way up until the other night. I ended up changing the thermostat (again) and cleaning debris out from in between the radiator and the condenser. Drained radiator out filled back up followed bleeding procedure to the "T" and now after im overheating while idleing after driving for 15-20 mins, but I have hot heat at an idle and while driving. I used the no spill fill during bleeding originally the other night. But still cant seem to get all the air out of the system. And the back bleeder screw while idling cap off has nothing happening at all. Put cap back on and loosen bleeder (now that there's pressure) and it bleeds out a little air then starts pushing out coolant. Im confused and need some advise. Or do I just break down and take it to a dealer and have them attempt it?