1)Coolant used or just water ?
2)Was a pressure test of the radiator done?

Using coolant will help identify leaks.. since it will leave stains... but water just evaporate quickly. I've identified 2 leaks easily before that was almost impossible to find with just water.


Some leaks only appear under pressure.. so a pressure test will help identify leaks in the vehicle cooling system. It's a simple job..

Well it's certainly easier than using plain water which leave no trace at all.. engine bay very hot, almost immediate dry up of any leaks.

I know Avanza has a lot of hoses.. but I wouldn't remove the engine just to check for leaks.

I would remove the engine to rip off and earn more money from customers.

Yes... but if filled with water already then not much coolant u can pour in. Anyway it will help to identify source of the leak.

Any will do since this is to help find the problem. .. But since it's a Toyota.. use Toyota long life coolant

Note : later after problem solved you probably need to drain and refill water plus coolant.. so any brand coolant will do to find the leak..

Hopefully not leaking into engine.. u might want to check engine oil see got oil + water mix also.