have a 2004 ford excursion 6.0 it been studded, it’ runs great. I just had a shop I’m my local area that works on Deisel trucks diagnosed that my oil cooler was bad they put new one and thermostat in last June for running high temps. They did a flush at the same time. So now a yr later they replaced the oil cooler for free and it’s still running a 19- 20 delta on highway at 70-75 mph. I have replaced the oil bypass valve and there was no change. So can anyone help me out??