I’m sure there is a thread on this but I can’t seem to find it. I have an engine noise on the pass bank and I have pulled the cam and rockers and lifters and they are in good shape. When turning the engine over by hand it makes one light tap noise and one a little louder every couple of revs. Seems weird just curious if anyone had heard this. When running it sounds like a typical valve train that doesn’t go away. Thanks for the info/help.

 

Did you roll the engine around to make sure there was no lash on any of the adjusters? If it's a tap, and it's under the valve cover, it's there somewhere. Only other thing i could think is a loose plug making a slight noise if it was loose.

 

When rolling it the lifters all stayed tight. The noise I’m hearing is lower when rolled by hand. Like wrist pin or piston slap maybe, maybe not. It could be nothing I suppose. I am replacing the rockers and possible the adjuster just incase.

 

I guess it's possible to hear piston slap rolling it by hand but I've never heard it by hand. Running with the impact of combustion yes. Sorry, don't have any suggestions other thanaybe something in the guids or chains. How many miles?

 

130,000 miles. I may be over thinking it. I’ll have to change the top end and see what happens.