You're probably sick of me mentioning this but I suggest you take the Patrol somewhere where they see zd30s daily like 4x4 obsession in Melton and make sure your timing over isn't leaking.

I was in the same mind set as you, thinking it was this and that, water pump, coolant tank... Hoping it wasn't the timing cover but in the end it was. At least that way you'll stop second guessing everything.

Tapatalked from S6