Isoflavones are found in small amounts in a number of legumes, grains, and vegetables, but soybeans are by far the most concentrated source of isoflavones in the human diet (104, 105) .
Standing water under a house is usually the result of only two things; either a leaking water line, or from surface water drainage around the house. If it was from a leaking water line, the leak would have to be substantial, and you would hear running water in the house.
On the highway, the car may reach temperature, opening the thermostat. Now the water is also going through the upper and lower radiator hoses and radiator. If there is a small leak in the hoses or radiator, that would cause overheating, now that the water is leaving the engine, (and is under pressure). A pressure test of the cooling system usually will show a leak. Especially if you notice fluid under the car after driving. A weak lower radiator hose could collapse at highway speeds but not lesser speeds around town. The most likely cause is a plugged radiator.