knocking or slapping noise 05 volvo ved12. please help!!!!!

Heck no. They are thin pieces of spring steel. I'd run the overhead at the same time.

 

Let me know what you find.

 

Exactly the same thing happened to my old 98 Volvo with d12a engine back in 2005. Number 5 exhuast rocker roller seized up and put ugly scratch on the exhuast cam lobe. I got metal shaving in the oil change plug magnetnand strange exhuast tone from the muffler. It sounded like a 2 stroke engine listening to muffler. So I just replaced the that roller and kept the old cam. I even changed it myself in one afternoon. Mine was without engine brake option so it was very easy. Old averitt express truck with 385hp without engine brake but only exhuast brake. I remember I paid 65 $ for that roller arm from volvo. I kept the old cam figured I could pay someone to change it if it went bad again. And Five year later I sold the truck without touching the cam. But I know if it had the engine brake option then it would a little bit more difficult. A lot more parts to move to get to the roller.

 

In my case the noise started coming from under the valve cover for maybe two weeks before I discovered the causes. I was doing local work so I didnt put a lot miles in that two weeks. The noise was less noticeable from outside than inside the cab. And I could hear it more clearly when the truck was coasting down. By the time I took it off the bearing inside the roller already gone. The roller turned flat spotted and the roller holder itself actually touching the cam. To this day I am still no sure what was the cause. I think maybe a small piece of debris in the oil passage got logged into the bearing and trashed it.