Check your coolant bottle

[UTVitz]

Any one else notice a sudden loss of coolant for no obvious reason-the bottle is just empty. No leaks and the level was fine a couple weeks ago. This happened after a sudden drop in outside temps into the single digits.

Sure made me nervous yesterday having recently read a thread where a smart car owner fried his engine because of low coolant and the light never went off because the sensor was in air-not actual coolant since the level was so low.

The toyota mechanic I use advised there may have been a pocket in the system that finally filled in-I'm thinking after a year and a half of driving? He did say he's noticed new cars are evaporating off more coolant than say cars from 10 years ago. He gave me a gallon of the toyota long life coolant that's in the car from the factory and I've topped up the system-it used about 1/3 of the gallon to refill it and will drive and observe if there are any other drops in it's level.