hi i helped a friend swap a B18C-R in his 97 EK hatch. we did the 3-wire to 2-wire IACV conversion, it started up fine, then the idle started surging. so we drained the coolant cleaned the IACV, but after installing it back on. we went to fill the radiator and it only took 1/4 gallon of coolant to fill up, we then drained it, replaced the thermostat, and tried again but something. after the 3rd time we got what feels like enough coolant in the system, but after warming up the engine, the heater blows hot air, but the lower radiator hose is still cold, there are no bubbles when the cap is off the radiator, the hoses are squishy when you squeeze them, and came to findout the radiator cap has a slight leak in it, so we tried a new one, now we have a slight howling sound coming from the timing belt area (water pump is brand new, but thinking water pump) and it doesnt seem like the fan is kicking on either. the fan, radiator and heater were all working prior to the swap a week ago. i have no clue whats going on and feels like the water pump isnt doing its job but its spinning the pulley, anyone had any ideas, tricks or know anything that can possible help me out please.

 

i forgot to mention it runs fine with the heater ON, but with the heater off it surges. it also runs surges only when the IACV is plugged in

 

ICAV might be bad. make sure you properly bleed the system too.
The sound from the water pump area is concerning.
Check the timing belt tension.

 

thanks for the input, i talked to another friend and hes saying the same exact thing you just said, i was having a feeling it might be those problems, just wanted to see if i was on the right track and not chasing ghost. ill give these ideas a try tomorrow and give a heads up

 

Also check all your vaccum lines and make sure everything is hooked up.

 

Check if any of your lines have shrinkage and I would check all fuses related to the radiator/fans etc.