hey guys,

I have a newly rebuilt 355 (all new parts on the inside) with about 500 miles on it. I have noticed a very slight knock when egine is cold and idling at 700 rpms. As soon as you idle it up (say to 8 or 900rpm no more noise. And then once the engine idles for 2 minutes or so it goes away for good. This was not a backyard rebuild as I had a machine shop do the work. Any ideas of what exactly would be doing the knocking.

PS. Cant really take it back for warranty as the build was done two years ago, just got it into the vehicle last month.

thanks for any responce.