i was having coolant leak from stock radiator so i swapped it to another used stock radiator.
However i noticed that the coolant level still drops very slowly over time.
Where could the leaking be? i inspected the radiator, upper and lower hose but they look fine.

 

could be head gasket and the coolant is going into the exhaust or oil.
do you smell coolant anywhere? do you see it dripping anywhere or on the ground after being parked for a while

 

i've had some crashes from drifting. i have very little oil leakage from one of oil pan bolts. (i see a few drops on the ground.) power steering fluid leaks.
Almost everytime i get out of the car, i think i smell clutch burn and tires. It's kind of hard to tell if i smell coolant.

 

change your oil and see if it has a brown milky color to it. you can also pull your spark plugs to see if they have a white residue on them. And also check in your coolant to see if you see any oil. All of these would indicate a head gasket issue. If you see any of these things you should stop driving it immediately .. it doesn't take long for coolant to muck up your oil and ruin your engine.

 

i did some research and found that the symptom of blown head gasket are over heating and white smoke coming out of the exhaust. But mine doesn't have those issues.

I checked out inside of my greddy radiator cap and found this. It looks like dirt..but it doesn't have that rough texture when i feel it. it kinda just melt(?).
the coolant in the radiator neck is green. did not find oil film in there.

Also i'm noticing that the radiator overflow tank hose(?) is getting whiter over time. why?

 

Perhaps it's turning white because there's a super small leak in it or somethin, who knows. Might want to start off with replacing that since it's cheap and easy.