David is absolutely correct. My issue was a plugged oil cooler. It was plugged with grit that I have been told is casting sand and silicates from using the gold colored coolant.
The plugged area was a pipe leading into the oil cooler that had an id of 5/8". Plugged solid allowing no coolant to enter. I had to flush the coolant 9 times with no t-stat to get most of that junk out. But my coolant filter still traps all kinds of stuff.
BTW Simple Green worked the best for cleaning the oil out of my coolant system. Better than dish soap, dishwasher soap, and WAY better than Purple Power.
Good luck
