oh no!

car has been running great even in heat. 2 weeks ago car slowed .05 lost 3 mph. got to looking and have water in oil. did a pressure test on cooling system, held 17 lbs for 2 hours, wth. committed to pulling eng. back car out of trailer and pulled up to garage door to open lower rad hose to drain water. come back in half hour to pull in and motor is locked up! pull plugs and no 8 full of water. at least I know where to look. its so hot today im just draining oil.