i just finished swaping out my head from a d15b8 to a 16 valve from a d15b2, i didnt change the waterpump or thermostat cus they were working before.

the guage is saying it isnt running hot but something is up when you pop the hood the radiator is super hot and the top hose is very hot but the bottom hose is ice cold so i dono , i am going to change the thermostat but does anyone know anything else?

LMK thanks

 

Change your thermostat

 

sounds like the pump

 

vapor lock - did you bleed the air from the system?

 

ye i somewhat bled it , i dono if there is actualy a problem or not i mean the guage isnt going any higher then it used to but the underhood temp seems to be higher, i have a fluidyne radiator and it gets hot as fuck which is always has so i dono maby there isnt a problem i dono i just drove it for like 30mins straight and it didnt overheat but the underhood just seems higher then before the swap