Air sucking into coolant system through rad. drain
 

noticed the other day very light dripping from the drain plug screw and rubber washer around it on my Koyo Radiator. this didnt change my level in the overflow

today the coolant buzzer went off for a few seconds, only occurred on angle in my driveway...tried to tighten the plug, the screw tightend up some but its leaking aroudn the rubber oring...anyways

car doesnt leak when running only when turned off and the amount leaking is VERY minimal...so minimal its not even registering as loosing coolant on my dipstick

is it possible that when the car is running on an inclined plane, air is getting sucked into the leaky plug (hence the reason its not leaking while running) which is forcing air up into the filler neck displacing water into the overflow/ast and allowing the buzzer to go off?

does express oil or napa/ advanced auto any normal places carry replacement drain plugs for koyo

No, but what is most likely happening is air is being sucked in through the leak when the cooling system cools instead of the coolant being pulled back from the recovery tank. I've never seen a Koyo radiator but I'll bet they use a common petcock that should be available at your local autoparts store.

i used one from the stock radiator when mine broke. also running a koyo. both were plastic and identical.

so where can these be found....any at nearby stores

i suggest doing a coolant pressure test bud.
get a pressure tester, and pump it up to 15psi. and listen closely for the hiss

Either try your local auto parts and see if you get lucky with a generic plug or call Malloy Mazda see the FAQ sticky for the phone number.