yeah, i know it's easy but what am i looking for?

 

Take off the valve cover and see how much sludge is in there. Try scraping some off (as gently as possible) with a screwdriver on a part that can get scratched (e.g. NOT the camshaft or any sealing surfaces). See how thick it is, etc.

 

You will know it when you see it. In addition, it may also form a varnish-like coating on your camshafts and other parts, which will be somewhat shiny and dark in color.