Burla, I want to thank you for all your posts over the years and replies to my recent questions. I decided to go with PUP 5W30 and a purolator boss filter I have been running the last two oil changes. I think it's just valvetrain noise for now. Going to try adding the extra 1/2 quart & see if that helps. If not, I will try Lubeguard Biotech. If that doesn't work, then I will try the Redline. Anyway thanks again!!