Coolant tastes sort of sweet depending on what "brand". If I taste it, I spit it out personally. It is poisonous but you have to have more than a couple molecules to do any harm.
Tyenol is poison too if taken in more than correct dosage. Take too much and say goodby to your liver.
You don't say what engine you have but I would do a complete inspection of the cooling system. Change the thermost and maybe the housing if it is the plastic kind, check/change any old hoses, flush the system, refil, burp it and then watch carefully after it gets to operating temperature.
Mike Holbrook
Meridian, Idaho
1992 535im, 17", Euro M5 Throwing Stars 8's & 9's, FK-451 235/45s & 255/40s, M5 Sway Bars 25/20, Conforti chip, Lowes Ram Air, glass sunroof