I think the coolant is coming from elsewhere...
Are your hoses hard when /after you have the engine running?
I have a lb7 that has excessive pressure in the hoses,i think...
But the point is it had numerous small leaks in the system because of the excessive pressure.I tightened all the offending clamps and the leaks disappeared,pretty much.
My truck is parked 98% of the time,it is a tow truck in a small town.So the issue hasn't made it's way to the top of the list.I add some coolant every 6 months or so depending on use.
On mine,my guess is an injector tube is leaking.
An uneducated guess based on what i have read here,i have never been inside a Dmax.
90 Chev 3500 c/c 4x4,6.2na,400 auto,4:10 gears.DSG Timing gears,main girdle, isspro tach, pyro,boost,oil and trany temp.Dual Tstats, High volume peninsular pump,on shelf, Custom turbo and intercooler 85%complete. Change of plans for the dually, it's going to get a Cummins. Both trucks are Blue 90 4x4 crews