engine oil in fuel: where could this come from?
I recently changed out my fuel tanks and noticed that the fuel was black. We also thought that it smelled like motor oil, but that could have been our imaginations at work. Anyway, I sent off a sample of the diesel suspecting asphaltene. The sample came back showing asphaltene, but it also showed flagged amounts of Phosphorous and Calcium and non-flagged amounts of Zinc. The labs comment was that it may indicate contamination with lube oil. Does anyone have any clues what could be happening here.
Also, I have located some asphaltene conditioner in spite of the fact that the Peterbilt and Cummins shop foremans had never heard of it. My question is will I just treat a few tanks or is this something I will have to use on a permanent basis?
The engine is a 1999 ISX that has high oil consumption. I have to add a gallon at about 5,000 miles, then about every 2,500 miles until the next PM. It was rebuilt about 90,000 miles back, but then sat for six years before I purchased it.
Is this a worthwhile discussion?