how about leak from the engine mismo?

it's true, baka sa makina na napupunta and tubig. check your engine oil kung kulay gatas (mixed oil and water- actually di talaga nagmimix ang tubig at langis. =) )

impossibleng matunaw yung tubig, it's liquid, siguradong may kinalalagyan yun.
naranasan ko rin yan dati, sa reserve napupunta and tubig. ewan ko kung bakit nagkaganon, kalaunan kumatok na makina ko.

have you noticed something wrong with your engine lately, baka you need to overhaul it na