My 07 was climbing a smallish hill, and began to make an odd rumbling under the hood on the passenger side. There was no overheating, and no warning lights. Steam from coolant begins to cook out from the passenger side, and there is gradual power loss beginning to happen.When I pull to the side of the road,the car dies, all the warning lights light up. The car will not restart, only the sound of the solenoid clicking. I roll down the windows to get some airflow, by the time the tow truck shows up, I roll them back up, but the car is acting like the battery is dying... any ideas?

Pretty amazing for such a new car. It may be a blown head gasket. I'd begin by performing the tests below:

https://www.askmehelpdesk.com/cars-t...ml#post2123675

Be sure to also run a compression test on each cylinder, which will tell you if the head gasket let go. When you last changed the coolant, did you use a 50/50 mixture of Toyota recommended antifreeze (likely DexCool) and distilled water?