04 g35 temp gauge hot no heat in car I changed rad

 

I had an air bubble recently on the heater core line because of a pinhole leak. Either get it inspected or feel which lines aren't hot (that's where your air bubble is).

 

OP you still need to bleed the system, as Urban suggested you have air in the system. Put the front end on jack stands which helps the trapped air to travel up and out, and use the bleeder screw by the battery to help get it all out. When you think you've gotten it all check both the upper and lower radiator hoses to make sure they're hot. Our cars are notorious for being a pain in the butt to bleed. Just keep at it and if you have to add coolant do it very slowly.