Okay this is a weird problem/question/opinion/whatever ... my truck is an '02 Dakota with the 4.7L with auto tranny with 21k miles on it... I changed the oil this evening and when I removed the big cap/plug where you pour the oil in, I noticed a rust colored sludge built up on the bottom of the cap and on the sides of the filler tube. This is the first time I have seen this and I religously change my oil every 2900 - 3000 miles. Has anyone out there experienced this phenonmenon/problem? If so has anyone figured out what the hell it is?