Massive radiator problem!
I have a 1997 3.8L, and when i bought it we discovered a black gunk near the cap of the radiator. Almost as if it were oil. We flushed it. Also the resevoir had half radiator fluid half black gunk. We cleared that out as well. Replaced it all with new fluid. Ok, fast foward a year, and here I am today with the same problem. More gunk. Its a thick black sludge. I can run my finger around the edge of where the cap sits (inside of course) and i will get a thick sludge on my finger with a little bit of clear liquid around it. I was told by some guy that it could be a leak sealer. Wouldn't that have been washed out with the first flush. Then wouldn't there have been a leak. If its something differen't like oil, what could be the cause. Oil is causing so many problems for me! Ugh! please help.