Gday tristan
Mate this has just happened to me in my 2015 sr5 hilux 200000 ks on it. I was losing about the same amount of coolant and could not for the life of me work out where it was going I gave in and took it to Toyota and they pressure tested the EGR cooler and found a pinhole leak it was also 60% blocked with soot I got them to replace it at a cost of $1000 I probably could’ve shopped around and got it a lot cheaper but I just wanted it done they also told me I’ve gotten to the kilometres where I will start seeing issues with soot buildup Ect. I thought Toyotas are meant to last forever. Good luck mate any other questions asked
