Need heat please!

I have a 1998 grand am 4cyl, 150k with a heater problem. The heat coming out is only warm never hot, doesnt matter if its vent/defrost/floor seems to be the warmest but not good enough. Blower works fine great air flow- just only warm air. I have replaced t-stat, coolant, heater contols, the engine temp is normal, inspetced all the accuators and they seem to be working fine. Also removed lower section of heater box to check the heater core and it was hot. Anyone have any suggestions? Im at a loss here. Should i just wait untill summer and sell it?

Does the blower direction work? I had a similar problem in my 95 that due to a vacuum leak, no matter where you put the blower dial, it would blow out a little in the top, the dash, and the floor.

Once I fixed the vacuum leak, it would blow fully through the vent selected and the heat was much hotter.

Yes the direction works in all positions, and has good air flow. Its just not getting hot enough. thanks for takin a shot! any other suggestions?

your heater core could be partially clogged , or your thermostat is a low temp,
what was the temp rating on that thermostat ?

Check the heater core lines when the engines hot and see if they are both warm/hot.