We used to see that type of goop when the owner/driver used high ash content multi-vis oil (typically 10W40) in conjunction with short cold drives & long oil change intervals. We would find this junk in the crankcase as well as the valve cover(s). Usually the first symptom was leaky VC gaskets. You run the risk of this junk plugging the oil pump pick up and starving the engine for oil. By the time the gauge dives (or the the dash light comes on), it is too late. Be careful & through in your cleaning. Good luck.