I have a 2003 Ford Powerstroke diesel and it stop on me while driving down highway. I had towed home and had a ford technician to come by to diagnose my issue. He ran several pressurized and computer type test. He found that the oil pump was bad. I had the icp, ipr, oil pump, and oil cooler replacedon it. I also did the egr delete. Well it started right up with no issues but after running it for about 15 to 20 minutes I noticed the coolant reservoir was dark. I opened the reservoir cap and there was oil in the reservoir very dark oil. It seems to be coming from the coolant hose from the intake. What’s causing this it has brand new cooler and it never showed this before the pump going out and no start. Oh yeah it’s a ford excursion. I’ve drained the coolant and refilled but still oil appearing I’m guessing while it’s cranking it starts slowly appearing.