so ive got a 92 honda civic cx with a 94 d15b7 in it and theres no leaks in the coolant system at all and it is full and bled the heater core doesnt leak but after driving for 20 minutes it barely starts to blow luke warm air never gets any hotter then barely warm im just wondering if anyone would know it a coolabt flush would help solve this or maybe a plugged up heater core?

 

mine did this exact thing and it was a thermostat that was stuck open

 

okay thank you i will have to try this and see