Civic EG

1994 Ex 4 door 1.6 auto with A/C

So recently I have been having an overheating issue. I cannot determine where the coolant is going. No visible leaks under car, oil is ok so it is not leaking through head. I did a radiator system pressure check and a block exhaust gas check and both passed ok. I pressure checked at 16 psi for about 5 min and it never dropped. I cannot see any smoke of any color coming out the back of the exhaust so I don't think the coolant is going through there.
I have replaced the thermostat and the radiator cap. still over heats. Fans kick on and both hoses get hot.
Kind of lost and don't just want to replace radiator, and definatly don't want to just do a new head gasket.
The only clue I have is that I get a lot of air bubbles going into the overflow bottle.
any suggestions ides or tips welcome. thanks

Air into overflow = air being forced into cooling system, possibly from combustion chamber. I'd do a compression check on each cyl. Let us know the #'s

you might have a washed out head gasket?!
my car did that and it didnt show signs of a blown head gasket until i got a compression text done and my rad geysered

check to see if there is a milky substance on the underside of your oil cap