Dear Members, I have an unusual issue with the Radiator in my VY, and welcoming other opinions, I have done a bit of work on it early this year, as it was over due for a few things to be done. Replaced the Supercharger Bearings and Front seal, and the Supercharger to LIM gasket, being I did notice there was a heap of oil between the 2 surfaces [LIM and S/C gasket] though I had rid this issue when I did a supercharger to LIM gasket, as the 2 rubber o rings were squashed down. I also replaced the radiator as the side tank was leaking, about the time after I replaced all the hoses, as it was probably the next weakest point, keeping in mind it was the original Radiator. I did a full radiator/engine flush that I purchased from Supercheap, and worked very well. I then flushed it twice with clean water, filled it up, took it for a drive, dumped that water, and filled it again and dumped it the 2nd time, this was about March this year. So it was almost crystal clear water. I also replaced all the hoses, and the Heater tap, so everything is clean again. So put coolant in it, and kept an eye on the water, and its is usually low at the end of each day, so I have just kept topping it up, thinking it was the readiator cap, So I purchased a new Radiator cap, I know its NOT leaking, water, so the only other options, its consuming it, and so the gunk has re-appeared "as per photo below", in saying that, I was going to do the LIM gaskets, but figured, it might be head gaskets, being if you pull a Super6 down that far, probably be best to the heads also, Being its in immaculate condition, so its a keeper, in saying all of that, your options are welcome to what may be causing it. As this may also assist other members. thank you in advance.