I changed oil couple of weeks ago and noticed very soft varnish/sludge on oil fill baffle in my 2006 V6 RAV4. I wiped it with finger at the time and thought it was gone, but I looked closed again today and there is some left (on the right). The last OCI was 10W30 QS Qtorque 5,000 miles/12 months, and before that 0W30 GC 3,000 miles/12 months, and before that various dino oils, mostly 5W30 every 6 months, 3,000-5,000 miles. Now I have 10W30 PP and the car has 50,000 miles, mostly short trips mixed with long hwy trips, and some boat towing. Should I worry about more of that varnish inside the engine and do some kreen cleaning? Thanks!