Before you pull the covers!!!!!!

If you're searching for a "tapping" sound, narrow down your search first.

You can use a screwdriver as a mock stethoscope before you tear anything down.

Simply put the plastic handle against your ear, and the metal end against the area you think the sound is coming from. Move the end of the screwdriver around to narrow down the area where the sound is coming from.

As to the covers themselves..... you want to get new gaskets to replace the ones that are there.....they will not re-seal themselves. You should get these before you do any work.

I'm pretty sure the small cover can stay on the big valve cover during removal. I could be wrong......just be careful during removal, if it doesn't feel right, it probably isn't.