So i just moved from western washington, to eastern washington yesterday. Temp difference is usually over 20 degrees. at the end of my trip, water sprayed out of the front and Immedietly pulled over. It got towed and taken to a shop where they kept it and checked it all out this morning. They said all they could find was that it was low on coolant and needed a new thermostat. They did that all and it traveled the remainder of the journey fine. it sat for a few hours then i proceeded to drive it around town about 30 min and when i got back, shut it down, it sounded like the coolant was boiling. I opened up the hood, there was nothing leaking, nothing appeared wrong it just was loud and sounded like something was "boiling". Could something more than just what happened be wrong, or am i just worried. My 4runner has never been in this hot of weather the entire time I have owned it. Any advice? Thanks!