I have a 98 Ford Expedition XLT 4x4 with the 5.4 motor. It's got about 170,000ish miles on it. I noticed the coolant was getting a little funky when I was doing an oil change, which was a bit low and checking everything. I was positive it was oil in there and was to full. Was brown nasty. So I flushed it real good and filled it back up. Was doing good, even drove from Missouri to FL and the GA and back to Missouri with no issues. Being back home again for awhile I started noticing it getting nasty again. So I checked everything out. Tranny fluid was good. Perfect not low no coolant in it. The oil was a bit low again but had no coolant in it either. I flushed it again and and have been trying to figure out where it is coming from. I am getting no leaks of oil on the ground. Now it's using oil like crazy and it's going to need flushed again as its bad now, not just dingy. It hasn't even been long. It's definitely oil and not tranny fluid in it. I am just stumped on what would allow the oil to go in there and no coolant to go into the oil. Help this stressed girl out!