The heat in my 04 g35 6mt sucks... i turn it up full blast and luke warm are comes out... anyone know an inexpensive way make my heat blazing?

 

Paint it red.

 

bleed your cooling system.
make sure your temp is set to 90 degrees

 

You have air in your engine's cooling system. Search the forum on using the Lisle No-Spill funnel to burp the air out of you cooling system. Not only does your heater core not create heat for the interior of the car....but if the air bubble in your cooling system moves into one of the heads, you'll overheat a headgasket and BOOM.....big bucks to repair the engine.

Here is how you use the funnel....which you can buy at Amazon.com:

 

i have the same problem in my 04 g35 coupe it only blows hot when foot on gas and when sitting it blows cold anyone know what to do to fix this ?