I checked my dipstick on my 2.5L in my '89 the other day and I have some kind of crusty/gummy particles in my oil. There were not very many of them but they were large enough to see with my eye and small enough to stick on the end of the dipstick. It was NOT metal however. Whatever it was is able to be crushed/squished into basically a liquid again and does not feel gritty or sandy. It almost feels like it is silicone that has been left inside oil so it denatures. What could this stuff be? The guy I bought the jeep from had the top end of the engine rebuilt before putting it into the jeep so could it be some byproduct of the assembly of the top end? Should I pull my valve cover and oil pan to investigate further? I have no overheating issues and normal oil pressure across the board.