what is this substance? Ground up plastic? How big of a deal is this? 2008 2wd 4cyl vvt-I 260,000

background info: owned for 8 years since 80k. Never seen this before. Always used K&n or Toyota filters and full synthetic oil changed myself every 5k. Changed oil just now. Black but no debris or signs of water. No oil in the water. No CEL. Not running bad or hot. Not making any weird sounds at idle or acceleration.

 

I have always had gunk under my cap with older/high mileage vehicles, personally I wouldn’t worry about it but if it’s concerning to someone else they may chime in. But if everything seems ok I would just clean it up put it back on and drive it

 

wipe it out and see how long it takes to come back...