I was driving last night and noticed my temp gauge go to red. Then I checked under the hood and there was steam coming out from what seams like rad cap. Today I let the car ran for 20-25 min and the temp gauge went back to RED and I could hear something boiling in radiator coolant tank and then steam coming out after I lifter the cap. What can this be? This should be pretty simple but I don't know much about Toyotas. Is this something simple like adding water or coolant to radiator or is it something more? The rad hoses seem to be ok and not torn.. thanks for your help!

 

Probably your thermostat is sticking. I would change out the T-stat and add more coolant.

 

If your motor is running fine, then my guess is that your thermostat go stuck closed or your water pump took a crap.

You can check for a blown HG by looking under the oil cap for a white film, hear/feel a miss, and there will be a sweet smeel to your exhaust.

But I don't think that is your problem. I'm going to vote for the thermostat or water pump.

You should make sure that you have enough coolant in your radiator too. And don't let it go to the red anymore. It will cause nothing but damage.