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With the warmish weather, having a properly maintained cooling system is important. If you pulled the car over at the time it overheated and let it cool down, you may be ok. First get it towed to a reputable mechanic and/or DIY the basic cooling system maintenance. That means new coolant, thermostat, thermostat gasket and radiator/reservoir cap. DIY cost is about $60. You'll also need distilled water and I would suggest replacing the radiator drain **** along with O-ring. If a mechanic does this, the cost can be for $75-$150. Make sure the coolant is Toyota red.
If lucky then the head gasket is still ok. If not, the coolant when refilled will look like a creamy chocolate milk when the car is running. If so, that means the engine will have to be torn down and rebuilt. You'll also notice a lot of steam out of the rear tail pipe.
Just to note to all members, with summer be sure your cooling system is ready for summer. We hate to hear of the car being junkyard material when this can easily be prevented.
Saw a car today driving down the road puking out lots of white steam from the exhaust.