Coolant Issue

[Jadeskyline]

Hey bro check your heater hoses regardless...i read that you bypassed it but check em neways....i had a similar problem (with no visible leaks showing from newhere)....i sat outside for weeks like a jackass bleeding the coolant system for maybe air bubbles in the system.....turned out to be tiny pinholes in my heater hoses didnt find out till the car got pretty hot and heard the hissing noise.....i could smell coolant (similar to ur problem) but could not find it event though i was losing coolant....when the car gets hot enuff the coolant turns to vapor which u will smell but not see leak but you will lose it nonetheless while driving....hope this helps and keep us posted gl