350 engine noise

Chevy Models Forum Camaro
1

Hello guys, My 1969 Chevrolet Camaro has a 350 engine. When I started the engine today, I noticed that cylinder #7 was making a clacking sound and that the engine was running rough. The noise disappears when I increase the engine speed. My engine sounds normal now that I have disconnected the spark plug to position #7. There was no jammed valve visible when I removed the valve cover.

Any suggestions as to what the issue might be?

2

It could be a few things. Check the lifters and rocker arms for any looseness or wear, and make sure the pushrod isn’t bent. You might also need to adjust the valve lash. If the issue isn’t there, look at the camshaft lobes and swap the spark plug and wire with another cylinder to rule out an ignition problem. A compression test can also help identify any deeper issues.