Overheating issue

[Cfc]

Do you have a link to a video or diagram of the petcock?

[CTScott]

Originally Posted by Cfc

Do you have a link to a video or diagram of the petcock?

Here is a view of it from under the car. Once you understand where it is, you can easily access it from above. A 10mm socket is necessary to open it.

Yaris - Coolant Petcock.jpg

[Yaristeve]

Is this petcock unique about this engine or do most modern engines have these now? I don't ever remember hearing/reading about such a petcock on older cars. And why wouldn't they put it on the head, at the highest point of the engine?

[CTScott]

Originally Posted by Yaristeve

Is this petcock unique about this engine or do most modern engines have these now? I don't ever remember hearing/reading about such a petcock on older cars. And why wouldn't they put it on the head, at the highest point of the engine?

I personally have only run into them on the 1NZ. I assume it is due to an issue where the path of water flow has a spot where air can collect and not be easily purged.