Dumb question

When topping off coolant. Pour into radiator cap hole or overflow? I’ll see my way out.

 

When you open the radiator cap it should be topped off already, if it's not pour some in there. The overflow has marks for "min/max" and should have coolant in there between those marks as well. As the coolant in the radiator/engine gets hot and expands it will flow into the overflow, and as the coolant cools down it will suck it back in from the overflow. Engine/radiator should always be topped off, overflow should have plenty since it's the excess the engine needs to suck/expand into.

Also use the same color the engine has, don't mix colors. Toyota stock color is pink, so don't pour green in unless you already swapped the engine to green in the past.

 

When cold the coolant level is below the low mark on the overflow tank. So was thinking of addding a little to get above the low mark. So you don’t go off the overflow level ? You go off radiator level?

 

Yup, I usually have mine at the "max" mark when cold. If you're lazy you can just pour some water in and it'll get diluted. Should be distilled water, but frankly I usually just use a water bottle if you're just adding a small amount like that.

 

Thank you.

 

OP quick safety tip: you might already be aware, but never try to remove the rad cap when the rad is hot. It’s under pressure and can send scalding fluid up at you.

 

If you need to pour directly into radiator don't forget to burp the system or you may overheat.