well I have a 90 STD and i just got done putting in a d16a6 and i took her out today and my upper radiator hose popped off. now right before this happend the temp guage spiked. All i have came up with so far as to why is the thermostat. the hose was on tight but the lip had been broken off so it probably just slid off. anyone have any other ideas? im picking up a new rad and thermostat this weekend so ill see how that works.

 

did you change the waterpump ? its possible the hose had a small leak to begin with and thats what caused the overheating and finally the hose ripped more till it fell off

 

The hose isnt ripped. its perfect. the upper radiator outlet is broken so it is only about half as long as it should be.

 

That is probably your problem..
It has to be able to hold pressure or it will overheat.

Some tips on bleeding the air out
once you install the new radiator can be found here:
https://honda-tech.com/zerothread?id=1123760