Hello! I've been browsing the forums for a while & finally decided to join. My '02 MCS has had a tap on the top end for a while that is very noticeable, even with the hood closed. It doesn't matter what oil I run in it, it doesn't seem to go away. I've changed the timing chain tensioner with no luck. I blew a head gasket & have decided to try to clear up this issue while while I'm in there. I've seen posts where some people have had luck with cleaning some oil passages, but I can't figure out which they're talking about and how to go about cleaning them, despite searching. I'm assuming these are the right ones?
https://i.imgur.com/eBjkJLX.jpg

Thanks for the help!

 

Listening.........